THE VERY FIRST attack from Leinster on Sunday seemed to spell impending disaster for Edinburgh.

This was the definition of a ruthless start from Leinster, who scored with their opening attacking possession of the Champions Cup round of 16 tie.

A lineout overthrow from Edinburgh bounced up perfectly for Josh van der Flier, who carried and set the platform for Leo Cullen’s men to strike without delay.

Hooker Dan Sheehan is one of the three Leinster players who race to the breakdown in a bid to ensure lightning-quick ball.

We can see Sheehan here on the ground after clearing out.

Sheehan ends up giving the scoring pass 15 seconds later after a typical show of effort and awareness.

In the meantime, Leinster snap straight from defensive mode at the lineout into their transition attack, which has been a big focus for the province this season.

Edinburgh have to switch from their attack plan into defending, and the lack of ideal organisation is evident as Leinster scrum-half Jamison Gibson-Park whips a perfect pass away to out-half Harry Byrne.

The spacings between Edinburgh’s midfield defence are wide, offering opportunity for Leinster.

Positioned around Byrne are number eight Caelan Doris [pink below] on his inside, Jamie Osborne [blue] on his outside, and left wing Jimmy O’Brien [green] hovering in behind him.

Byrne is decisive in darting at the line on the inside shoulder of Edinburgh number 12 Jamie Lang.

Byrne senses that Lang will turn in to tackle him, which is exactly what happens.

So as Lang jams in on Byrne, Edinburgh number 13 Matt Currie [yellow above] suddenly has a crucial decision to make.

Does he jam infield to O’Brien? Or does he stay out on Osborne?

He has mere split seconds to make his decision and Byrne makes it all the more difficult by disguising his intention.

At this moment, it’s still possible for Byrne to release a pass wider to Osborne.

Currie reads that pass onto Osborne but Byrne instead drops the ball off short to O’Brien.

It’s a lovely bit of heads-up rugby from Byrne and Leinster to make the break soon after the turnover of possession.

O’Brien straightens up and sprints upfield.

He has Rieko Ioane [yellow below] working up on his outside and a pass to the Kiwi at this stage might give him a chance to finish, even if Edinburgh wing Malelili Satala is close to Ioane.

But O’Brien has already decided to slalom to his left to connect with the supporting Gibson-Park.

With Edinburgh scrambling hard, O’Brien dummies and carries before Ioane and Osborne arrive to clear out the breakdown.

It means another rapid recycle and a chance for Leinster to finish.

Byrne initially gravitates towards the ruck to make sure he is the clear first receiver. It looks like he will push Doris outside him…

… but Byrne realises that with Gibson-Park’s passing range, he can slide into a wider receiving position to exploit the numbers-down Edinburgh defence.

Gibson-Park gets great velocity on his pass to hit Byrne on his fading line, meaning the Leinster 10 gets outside the advancing Currie [yellow below] and can draw in next defender Lang.

While that’s happening, Sheehan [yellow below] is working hard to sprint out towards Leinster’s right edge from his involvement in the ruck just inside his own half.

Byrne, Hugo Keenan, and Sheehan then do an unfussy job of giving Tommy O’Brien plenty of time and space to finish in the right corner.

It’s a cracking, clinical try from Leinster with their first attacking possession of the game, O’Brien dotting down with just 1:07 on the match clock.

Having put an onus on improving their transition attack, it’s pleasing for Leinster to be scoring tries like this as they take advantage of the disorganised Edinburgh defence.

After that crisp start in attack, an element of sloppiness slipped into Leinster’s play despite some good build-up work.

Ioane threw a poor pass over O’Brien’s head and into touch down the left after more smart transition play from a brilliant Keenan aerial win, then Byrne had a forward offload to Gibson-Park.

These kinds of passing and handling errors have caused plenty of frustration for Leinster so far this season, although their hope is that they become less and less frequent as their cohesion grows.

No team can have a positive outcome on every single possession and this team is judged to the most exacting standards, but reducing their error count remains a work in progress for Leinster. 

And yet, Leinster had lots of positive outcomes in this game as they scored seven tries and produced some of their slickest attack of the season.

Their second try, again through Tommy O’Brien, was a nice first-phase score from a left-hand-side scrum in Edinburgh’s 22.

With Edinburgh right wing Darcy Graham in the frontline defence, rather than sweeping across in behind, Leinster know that if they can get him outside that frontline, O’Brien has a fine chance of scoring in the corner.

They’re helped hugely by a dominant scrum, which earns Leinster penalty advantage as tighthead Furlong gets upfield.

Doris scoops the ball from the base to Gibson-Park, offering an immediate element of width, and he quickly moves it onto Byrne.

This time, Byrne doesn’t want to dart at the defensive line at all. He actually stops moving forward as he receives the ball, intent on moving it on without delay.

Ioane runs an ‘overs’ line off Byrne, meaning he fades away from Byrne on the pass.

As with Byrne, there isn’t much forward movement from Ioane initially as he instead runs out across the pitch.

He backs his acceleration and Byrne’s pass to get him outside Edinburgh wing Satala.

And as Ioane does so, Edinburgh fullback Piers O’Conor closes up and in from his wide starting position.

Ioane could hit Keenan just outside him here, sending him racing outside O’Conor to potentially score.

But Ioane opts for the much longer pass to O’Brien, around 30 metres away.

It’s a class left-handed pass from Ioane as he’s moving at speed.

O’Brien is still a good 20 metres out, but he has the acceleration to get beyond the scrambling Satala for a clinical finish into the right corner.

There was a similar pattern after Leinster’s second try, however, as they produced another couple of errors in the following few minutes.

One of them led directly to Edinburgh’s opening try.

Leinster decide to run the ball out of their own 22 from a defensive lineout. They initially make progress up the left before play breaks down in midfield.

Byrne plays out the back to Ioane, who squares up and seems to expect Furlong to run a flat, short line off him.

Osborne is out the back of Furlong, and he also seems to expect the tighthead prop to accelerate on that flat line just outside Ioane.

Instead, Furlong slows his feet in a bid to give himself time to catch-pass before he’s hit by Edinburgh out-half Ross Thompson.

But Osborne is right on top of Furlong and the ball fizzes straight across his face, bouncing up into the hands of Charlie Shiel for a handy Edinburgh try.

This rather bizarre pattern continues right through to half time as Leinster produce some slick attack and then almost immediately make errors.

Jimmy O’Brien’s try is sharp, with Leinster’s pack mauling infield to create a shortside.

Gibson-Park signals for Byrne to swing into the shortside.

Sheehan has a dart off the maul, which attracts Edinburgh scrum-half Shiel in towards the ball.

Gibson-Park, Byrne and O’Brien then take full advantage of their forwards’ excellent work by finishing in the left corner.

It’s another slick catch-pass by Byrne under pressure from Graham.

And yet, Leinster are soon back under their own posts after another error.

This time, they look to run from an Andrew Porter breakdown poach near their 22-metre line.

Osborne receives a pass from Sheehan and seems to decide early that he wants to hit Gibson-Park on his inside.

The relative lack of deception makes it easier for Edinburgh to get a read on Osborne’s intention.

At the stage below, Edinburgh flanker Dylan Richardson [red] can already commit to tackling Osborne, despite the presence of two Leinster players outside Osborne.

That, in turn, means Thompson doesn’t need to work out onto Osborne, so he adjusts back infield towards Gibson-Park.

Thompson ends up ideally placed to fill the passing channel, getting his hands up late for an intercept as Osborne passes towards Gibson-Park.

It’s another straightforward score for Edinburgh without them applying much defensive pressure.

Leinster have a couple of misses down in the Edinburgh 22, with Gibson-Park’s offload just evading Keenan, then Porter losing the ball forward after some positive phase-play attack.

But it clicks again in the 37th minute as fullback Keenan finishes Leinster’s fourth.

Again, they strike from a close-range lineout, with the speed and snap of the Leinster attack leaving Edinburgh struggling to cope.

On fourth phase, Ioane does a good job of engaging two defenders before releasing the ball early enough to give Keenan time to use his footwork to beat the late-folding Satala. 

But yet again, momentum swings quickly back away from Leinster.

Again, they’re picked off by Edinburgh.

This time, it comes on first phase as Gibson-Park runs a loop play around Byrne off a scrum.

Currie does an excellent job in defence for Edinburgh here.

Leinster’s hope is that Ioane’s short line off Byrne will sit Currie down.

And as Byrne runs at Edinburgh, it initially looks like that is the case.

In this split second above, it looks like Currie [red] has bitten down on Ioane’s line, which should leave space outside him for Gibson-Park to run into if Byrne can find his scrum-half with the pullback pass.

But Currie reads off Ioane at a very late stage, shifting up into the space where Byrne has passed to.

Ioane might reflect on whether a slightly wider starting angle for his run might have helped him to tie Currie down further, but it’s simply good defence from the Edinburgh centre.

As we can see below, Gibson-Park is stretching back on his inside to try to collect what is a vertical pass from Byrne.

It’s tough to get more velocity on these late pullback passes and Currie is able to crowd out the space and win the ball before Gibson-Park can reel it in.

He streaks away to score just before half time.

Leinster struggle for end product with their attack early in the second half, with van der Flier knocking on over the tryline and then getting choke tackled. A Byrne chip kick comes to nothing in Edinburgh’s 22, then Furlong knocks on a Ryan Baird tip-on pass.

All of which leads to the visitors taking a scarcely believable lead through Graham’s excellent try, which begins with a fortunate ricochet from a blocked Thompson kick.

So Leinster find themselves behind at 31-28. 

Their attack needs to deliver again. And it does. First, from a five-metre tap penalty play.

As Sheehan taps and carries on first phase, van der Flier stays tucked in behind.

And on second phase, van der Flier swings behind the hard-running Caelan Doris to offer a late threat to the Edinburgh defence.

Doris’ running line initially attracts Edinburgh flanker Liam McConnell [red below].

McConnell then has to switch out onto van der Flier at a late stage, with lock Glen Young outside him similarly reactive. They can’t land a strong shoulder onto van der Flier, who dominates the collision and gets a clean finish.

Now back in front and in control, Leinster pull clear with two more well-taken tries. 

The first comes from another Keenan aerial win under a towering Byrne garryowen – Leinster no longer taking risks in trying to run out from their own half.

Their transition attack sparks into life as Joe McCarthy, Doris, and Robbie Henshaw move the ball cleanly to Ioane, now playing on the left wing.

The width of Gibson-Park’s initial pass to McCarthy is important, allowing Leinster to immediately target the space out wide after Keenan’s aerial win.

Ioane surges into the 22 and steps inside O’Conor, before an excellent clearout by Henshaw and Osborne.

Lang is a turnover threat here but Henshaw makes initial contact, difficult with Graham on the ground having tackled Ioane, before Osborne arrives in with an impactful second shot.

The ball is left on a plate for Gibson-Park. That gives him the time and space to scoot away from the breakdown and pick out the best space.

Gibson-Park finds tighthead prop Thomas Clarkson accelerating onto the ball against the reeling Edinburgh defence.

Clarkson does well to tuck the ball into his left hand, leaving his right arm free to help him fight off the despairing challenge from Freddy Douglas before reaching out to dot down.

It’s Ioane who puts the final seal on Leinster’s win, with Gibson-Park delivering another scoring pass.

This one stems from Leinster’s aggressive defence earning a turnover. Gibson-Park [green below] has been defending out wide on the left.

Sheehan steps in at scrum-half as Leinster again click into their transition attack with a sweeping sequence of passes from Baird, Keenan, and Byrne.

Gibson-Park does his thing as a makeshift fullback/outside centre. His pass on the edge to execute a 3-on-2 is a thing of beauty.

Gibson-Park has impressed in the back three for Ireland on a couple of occasions in recent years, and it would be fun to see him playing full games there, such is his all-round class as a rugby player.

In this instance, he frees Ioane and works hard in support on the inside, providing a return pass option.

Despite Shiel calling for Graham to take Ioane, with the scrum-half blocking the passing channel to Gibson-Park, the Edinburgh wing goes for one more intercept.

Graham commits to the intercept attempt a hint too early, and the experienced Ioane reads the cue, dummying and finishing into the left corner.

Ioane’s try copperfastens a Leinster win that featured some slick attack, some sloppy attack, and some in between.

Ultimately, 49 points scored and seven tries mean they’ll have been pleased, but the points Edinburgh scored off Leinster’s attack leave them with room for improvement ahead of this weekend’s quarter-final against Sale.