This season's first Champions Cup semi-final is an all-English affair, with Premiership champions Saracens facing Wasps in Reading.
Saracens' imperious form in 2015/2016 has made them the team to beat in Europe but unlike in previous seasons when they've come unstuck against the likes of Toulon and Clermont, it's a Premiership rival that now stands in their way of getting a shot at a first European title.
The only problem for Saracens is that the last time they faced Wasps, Dai Young's improving side stunned everybody by thrashing Saracens 64-23 on their own turf.
By combining the power of Billy Vunipola with the finishing of Chris Ashton, Saracens have a variety of attacks with which they can grind opposing sides down.
Wasps on the other hand have been all flair – a virtuoso backline featuring Elliot Daly, Frank Halai, Christian Wade and of course Charles Piutau, complimented by the pilfering at the breakdown of George Smith, a leading contender for this season's European Player of the Year award.
As well as winning the joint most turnovers (10), George Smith has also made the most tackles in the Champions Cup this season (94/107). Piutau meanwhile, who heads to Ulster next season, tops the charts for defenders beaten (31), metres made (714) and clean breaks (15) in the Champions Cup so far.
It took Jimmy Gopperth's last-gasp conversion to put away Exeter away and allow Wasps to reach this stage, but Saracens exude confidence. What a semi-final awaits.
In teams news, Saracens half-back Richard Wigglesworth will make his 150th appearance for the club on Saturday, lining up alongside Owen Farrell in the halves.
At centre, Brad Barritt captains the side and is joined by Scotland international Duncan Taylor. On the wings, Chris Wyles and Chris Ashton continue with Alex Goode named at full-back.
Up front, Mako Vunipola, Schalk Brits and Petrus Du Plessis make up the front row with Maro Itoje and George Kruis named at lock. In the back row, Billy Vunipola packs down at number eight alongside Michael Rhodes (blindside flanker) and Will Fraser (openside flanker).
Meanwhile James Haskell will captain Wasps, nine years on from Wasps’ last Champions Cup Semi Final, when the back-rower made a try-scoring appearance as a substitute in Wasps’ win against Northampton Saints (2007).
There are two changes to the Wasps’ squad that beat Exeter Chiefs in the quarter-final.
Lorenzo Cittadini packs down at tighthead, while Bradley Davies starts in the second row alongside Joe Launchbury, with Jake Cooper-Woolley and Kearnan Myall ruled out through injury.
Phil Swainston and Sam Jones will be ready to provide reinforcement from the bench.
Looking ahead to Saturday’s European knockout match, Dai Young said: “The players know how big this game is, so there hasn’t been much that has needed to be said this week – we certainly don’t need any extra motivation. The players are excited and looking forward to it, as I’m sure are our Wasps’ fans and everyone associated with the club.
“This week, it has just been a matter of doing what we normally do, making sure preparation is good and that we are all clear on our roles and responsibilities. Saracens have probably been favourites for the title from the word go really. They are a quality team and have plenty of experience at this level, so we will have to be at our best on Saturday. If we achieve that and do play to the best of our ability, we know we can cause any team problems.
“Our Wasps fans’ have been incredible all season and hopefully they will turn out in force at the Madejski Stadium to support the players in the biggest game of our season so far. These European occasions don’t come around too often and should be savoured. It’s been a long wait to make the last four in Europe and we don’t want our European journey to end here.”
Form: This will be the first time the clubs have met in European competition. Saracens have won just one of four previous Champions Cup semi-finals, beating Clermont 46-6 in 2014, the biggest margin of victory in a tournament semi-final. This will be Wasps' third Champions Cup semi-final appearance; they won both previous matches at this stage and went on to lift the trophy on both occasions in 2004 and '07. Saracens remain undefeated in the Champions Cup this season; no side has ever won the competition after winning all their pool games. Wasps have lost just once in their last 22 Champions Cup fixtures when they've scored 25 points, a total they've achieved five times already this season.
Saracens: 15 Alex Goode, 14 Chris Ashton, 13 Duncan Taylor, 12 Brad Barritt (c), 11 Chris Wyles, 10 Owen Farrell, 9 Richard Wigglesworth, 8 Billy Vunipola, 7 Will Fraser, 6 Michael Rhodes, 5 George Kruis, 4 Maro Itoje, 3 Petrus du Plessis, 2 Schalk Brits, 1 Mako Vunipola
Replacements: 16 Jared Saunders, 17 Richard Barrington, 18 Titi Lamositele, 19 Jim Hamilton, 20 Jackson Wray, 21 Neil de Kock, 22 Charlie Hodgson, 23 Marcelo Bosch
Wasps: 15 Charles Piutau, 14 Christian Wade, 13 Elliot Daly, 12 Siale Piutau, 11 Frank Halai, 10 Jimmy Gopperth, 9 Dan Robson, 8 Nathan Hughes, 7 George Smith, 6 James Haskell (c), 5 Bradley Davies, 4 Joe Launchbury, 3 Lorenzo Cittadini, 2 Carlo Festuccia, 1 Matt Mullan
Replacements: 16 Ashley Johnson, 17 Simon McIntyre, 18 Phil Swainston, 19 Sam Jones, 20 Thomas Young, 21 Joe Simpson, 22 Ruaridh Jackson, 23 Rob Miller
Date: Saturday, April 23
Venue: Madejski Stadium, Reading
Kick-off: 15:00 BST (14:00 GMT)
Referee: Romain Poite (France)
Assistant Referees: Jérôme Garcès (France), Pascal Gauzere (France)
TMO: Eric Gauzins (France)