Both sides have left a trail of victims in their wake en route to the competition’s showpiece, with Leinster only the second team to reach the final with a 100 per cent record.
The Irish province have already dispatched the Premiership champions Exeter, Top 14 leaders Montpellier, Champions Cup holders Saracens and defending Guinness PRO14 champions Scarlets.
Only Racing 92 now stand in their way of a fourth European triumph, after the French side reached only their second final with a 27-22 victory against Munster in the last four.
The beaten finalists in 2016 suffered two defeats as they progressed to the knockout stage as runners-up, before dismissing Clermont in the quarter-finals.
We’ve had a look at two of the key head-to-head battles in the forwards and the backs ahead of the final which could decide who lifts the trophy at San Mamés Stadium.
Devin Toner v Donnacha Ryan
Together they made up Ireland’s second row for the famous win over All Blacks back in 2016, but Devin Toner and Donnacha Ryan will be on opposing sides on Saturday.
Toner has been a vital cog in Leinster’s wheel alongside James Ryan, who is yet to lose a professional game in 20 outings, featuring in the victories over Saracens and Scarlets.
The giant Ireland international is a dependable presence at the lineout, providing the platform to allow Johnny Sexton to thrive, while his experience will also be key – with three European finals already under his belt.
🔵Can @leinsterrugby make it four? 🏆🏆🏆🏆
— PRO14 RUGBY (@PRO14Official) May 10, 2018
His former international team-mate will provide a worthy advisory, though, with Donnacha Ryan’s influence one of the main reasons Racing 92’s lineout defence is regarded as the best in France.
Ryan will know his opponent well, having played alongside each other for at least two years, and his ability to disrupt the throw-in will leave Leinster no room for error.
The former Munster man made the difference as Racing 92 defeated the Irish province in the semi-final, competing consistently at the lineout and delivering a huge defensive performance.
Isa Nacewa v Teddy Thomas
Leinster legend and captain Isa Nacewa will want to go out on a high by leading the Irish province to another European crown before retiring at the end of the season.
The 35-year-old utility back, who had already hung his boots up once before being persuaded to return by Leo Cullen, makes the game look effortless and can dance around defenders.
Having previously won three European titles with the club during his first five-year stint, Nacewa’s experience of the big occasion could also prove important in the final.
The Fijian will certainly need to be at his best to shackle Teddy Thomas, who was at his electric best as Racing 92 ripped through Munster in the opening half-hour of their semi-final against Munster.
He scored two tries and handed a third to captain Maxime Machenaud when he only needed to dot down himself for a hat-trick as Racing 92 sprinted into a 24-3 lead.
If Thomas can deliver a repeat performance in the final then Racing 92 will fancy their chances of upsetting the odds, but Nacewa is unlikely to be quite as accommodating of the Frenchman.
Guinness PRO14 Final 2018 Ticket Information: Prices start at just €35 at www.ticketmaster.ie with tickets available to suit every experience.
To book hospitality, visit: https://www.pro14rugby.org/hospitality
For Travel packages, visit: https://www.pro14rugby.org/travel-packages
For Fanzone & Dublin 7s, visit: http://www.dublin7sfestival.ie