Ulster are looking to become the first team ever in the PRO12 to win a semi-final on the road when they face Leinster in Dublin on Friday.
After finishing the regular-season in fourth position, they have to travel to the Irish capital where the PRO12 table toppers lie in wait.
Scoring six tries in a victory at the Ospreys would have been a huge confidence booster for Ulster while Leinster brushed aside Treviso 50-19 which, because of Connacht defeating Glasgow, meant they ended on top of the pile. Now comes the knockout stage and a mouth-watering game.
Revenge could also be in the air following Ulster's 30-6 victory in April at Kingspan Stadium, which was led by Paddy Jackson's 18-point showing. In the match earlier in the season at the RDS, Leinster ran out 8-3 winners in a low-scoring contest that saw Sean Cronin cross.
Ulster director of rugby Les Kiss is understandably wary of Leinster after that recent fixture, but with his side's attacking game looking in good shape, don't expect the visitors to keep things tight and cautious. They have star backline talent and will rightly let them play.
Kiss has the luxury of naming the same squad from that Liberty Stadium win for this week's showdown as Stuart McCloskey and Luke Marshall continue in midfield. Darren Cave offers plenty of experience as a back-up on the bench.
It will be a special occasion for Chris Henry, who will win his 150th cap for Ulster. The 31-year-old made his debut in the 21-10 European Cup win over Harlequins in January 2009 and has scored nine tries in his appearances to date. Henry is joined in the back-row by Iain Henderson and Sean Reidy.
Captain Rory Best, Callum Black and Ricky Lutton will form the front-row, with locks Pete Browne and Franco van der Merwe completing the pack.
Leo Cullen has been forced into making one change, however, as Rob Kearney fails to shake off an ankle problem. As a result Luke Fitzgerald returns to the left wing with Isa Nacewa captaining from full-back. With Fitzgerald starting at 11, Dave Kearney moves to right wing.
Ben Te'o and Garry Ringrose are the centres for the 12th time this season as Te'o starts for his last time in Dublin before his move to Worcester, with the sell-out crowd hoping to play a factor in what should be a thrilling derby.
Ones to watch:
For Leinster: He has been superb for Leinster since returning to the province and his Man of the Match performance two weeks ago was another reminder of just how key Isa Nacewa is to this team. A real leader from wide out, Leinster will need all of his experience and solidity to shine through if they are to defeat Ulster. Also keep an eye on powerful centre Ben Te'o, who has been in devastating form in recent games.
For Ulster: So often in big games Ruan Pienaar has stood up for Ulster and they need him to do it again on Friday. His calmness and game-management from the base is so often under-rated and if he can put Ulster in the right areas with the boot, thus taking some pressure off his fly-half, it will be a significant boost to the visitors' chances of winning. That combination is vital to Ulster's hopes of victory.
Head-to-head: The battle at fly-half is going to be an intriguing one as Jonathan Sexton clashes with Paddy Jackson. Jackson has not been in the mix for Ireland in 2016 so far but a big performance against Sexton would surely give head coach Joe Schmidt plenty to think about ahead of their upcoming trip to South Africa. If he can click with his impressive centres, Jackson could well come out on top in Dublin.
Form: Leinster's only defeat in their last four fixtures was 6-30 to Ulster in Belfast in Round 21. The Leinstermen have not been defeated in the PRO12 at RDS Arena since Dragons were the visitors in 2015. Leinster's record in PRO12 play-offs (including the Celtic League semi-finals) is a perfect played six, won six. Ulster have won their last four PRO12 matches since their reversal at Glasgow Warriors on 25th March. The Ulstermen have won just one of their six previous play-offs/semi-finals in the tournament; 28-17 at home to Scarlets in 2013. The last four regular season PRO12 meetings between the two provincial rivals have all been won by the home side on the day. The two sides have met on six previous occasions in the knock-out stages of all competitions with the only time that Ulster avoided defeat being a 23-all draw (AET) in the quarter-final of the Celtic Cup in 2003 with Ulster progressing to the semi-final having scored more tries. Ulster's only victory in 12 previous visits to RDS Arena was 22-18 in the Guinness PRO12 in March 2013.
Prediction: Don't expect either side to win by more than five or so points on Friday. It should go down to the wire. Leinster by three.
Leinster: 15 Isa Nacewa (c), 14 Dave Kearney, 13 Garry Ringrose, 12 Ben Te'o, 11 Luke Fitzgerald, 10 Johnny Sexton, 9 Eoin Reddan, 8 Jamie Heaslip, 7 Jordi Murphy, 6 Rhys Ruddock, 5 Mick Kearney, 4 Devin Toner, 3 Mike Ross, 2 Richard Strauss, 1 Jack McGrath
Replacements: 16 Sean Cronin, 17 Peter Dooley, 18 Tadhg Furlong, 19 Ross Molony, 20 Jack Conan, 21 Luke McGrath, 22 Ian Madigan, 23 Zane Kirchner
Ulster: 15 Jared Payne, 14 Andrew Trimble, 13 Luke Marshall, 12 Stuart McCloskey, 11 Craig Gilroy, 10 Paddy Jackson, 9 Ruan Pienaar, 8 Sean Reidy, 7 Chris Henry, 6 Iain Henderson, 5 Franco van der Merwe, 4 Pete Browne, 3 Ricky Lutton, 2 Rory Best (c), 1 Callum Black
Replacements: 16 Rob Herring, 17 Kyle McCall, 18 Andrew Warwick, 19 Robbie Diack, 20 Roger Wilson, 21 Paul Marshall, 22 Stuart Olding, 23 Darren Cave
Date: Friday, May 20
Venue: RDS, Dublin
Kick-off: 19:45 BST (18:45 GMT)
Referee: Ian Davies (WRU)
Assistant Referees: Ben Whitehouse, Sean Brickell (both WRU)
TMO: Jon Mason (WRU)