What. A. Howler.

If Wasps lose this match then Willie Le Roux might want to steer clear of social media tonight.

He dives over the line but lets the ball slip out of his grasp before touching down. Howls of derision from the home fans accompany his walk back.

Image source, Rex Features

Wasps are back in the game! Hang on. Are they? 

Wing Willie Le Roux sees plenty of green open up in front of him, when he is picked out by Kurtley Beale after a dazzling run, opening that stride to see off Joey Carbery and touch down.

Or at least we think he has touched down. There appears to be a problem with the grounding...

Remember the time and the place. Johnny Sexton shins a kick into touch. He looks shocked.

Dan Robson eases the pressure with an incisive kick which cuts open the Leinster defence like a ripe watermelon.

Full-back Joey Carbery looks to be in a sticky spot momentarily, but recovers quickly and then Leinster break.

Leinster continue to look dangerous going forward, Sean O'Brien leading the charge following that home line-out.

Away defenders are scattered all over the place, but the Premiership side get enough numbers back to win a line-out.

Image source, Rex Features

Uh oh - Wasps are all over the shop. Exemplified by Danny Cipriani smashing a kick out on the full. The Aviva crowd love that...

Wasps play their get out of jail card. Leinster's attack - led by Garry Ringrose and Robbie Henshaw - punch through the Wasps defence, only to see Dan Robson and Danny Cipriani combine to prevent any serious damage.

Image source, Rex Features

Wasps threaten with a driving maul, but the Leinster defence holds out and wins a scrum about 5m from their own line. The ball wriggles out to Leinster skipper Isa Nacewa who hoofs upfield to relieve the pressure.

Wasps have not let that early penalty affect them. They're straight on the front foot from the restart. Plenty of pressure in the Leinster 22..,

You didn't doubt him, did you? Johnny Sexton steams over the penalty from out wide. First blood to Leinster.

Johnny Sexton starts to get that right boot working. He pumps one behind the Wasps backline, Kurtley Beale scurrying across to dance his way out of a tight spot. 

Sexton goes crossfield with his next kick, Leinster winning a kickable penalty when Joe Launchbury is punished. 

First chance goes to the home side...

Intense start. We are cooking. Leinster go through the hands from their own 22, trying to ask questions of that Wasps defence. They are answered, Wasps winning the first penalty of the afternoon after a Leinster shirt strays offside.

Image source, Rex Features

The talking stops. The rugby starts. Wasps fly-half Danny Cipriani boots us under way...

Leinster:  Carbery; Byrne, Ringrose, Henshaw, Nacewa; Sexton, McGrath; McGrath, Strauss, Furlong, Toner, Triggs, Leavy, O'Brien, Conan.

Replacements:  Tracy, Healy, Bent, Molony, van der Flier, Gibson-Park, McFadden, Kirchner.

Wasps:  Beale; Wade, Daly, Gopperth, Le Roux; Cipriani, Robson; Mullan, Taylor, Cooper-Woolley, Launchbury (capt), Myall, Haskell, Young, Hughes.

Replacements:  Johnson, McIntyre, Moore, Symons, Rieder, Simpson, Leiua, Bassett.

Referee: Nigel Owens

Leinster have recalled eight Ireland players for the visit of Wasps.

Among the returning internationals are Johnny Sexton, who will start at fly-half, prop Jack McGrath and second row Devin Toner.

Premiership leaders Wasps have England internationals Joe Launchbury, Elliot Daly and Nathan Hughes in their side for their Champions Cup quarter-final.

The trio are among six changes from the 40-33 Premiership win over Worcester last Sunday.

Both sets of players are lined up in the Aviva tunnel. The mood music is blaring, the flame machines are firing. Almost showtime.

Time for a quick check on the teams...

Leinster head coach Leo Cullen, speaking to BT Sport: "It is going to be a tough challenge against a very good Wasps team riding high at the top of the Premiership.

"We played them twice last season in the group stages and they were tough games. But this is the sort of occasion that we want to be part of."

Wasps director of rugby Dai Young:  "It's going to be a fantastic occasion - nearly 50,000 in the stadium against a quality team.

"The majority are going to behind Leinster but we'll have fantastic travelling support.

"We're probably underdogs - not many teams have won away in European quarter-finals - but it's up to us really do something extra special."

Anyway...enough about the summer. Let's focus back on today, shall we?