Racing 92 stretched their Top 14 winning run to five matches with a dramatic defeat of Toulouse.
Toulouse safeguarded the future of their France full-back Thomas Ramos as the Top 14 club entered into the festive spirit on Christmas Eve.
The teams who finished first and second in the Top 14 regular season will contest the final after Clermont Auvergne got the better of Lyon.
Top 14 leaders Toulouse enjoyed a fine day as several rivals were beaten amid a series of dramatic finishes.
Leinster will be led by the fit-again Johnny Sexton when they take on Toulouse in Sunday’s European Champions Cup semi-final.
Sofiane Guitoune’s 77th-minute try carried Toulouse past Clermont Auvergne as the top two in the table served up a Sunday treat.
Toulouse are now unbeaten in 14 Top 14 matches after grinding it out at La Rochelle, while Racing 92 got the better of Bordeaux.
The Top 14’s leading two both won on Sunday, but it was Toulouse’s bonus-point success that grabbed the attention.
Toulouse replaced Clermont Auvergne at the summit of the Top 14 table on Sunday, while Toulon scored two late tries to stun Stade Francais.
Toulouse ended 2018 on a high note, dishing out a crushing defeat to Toulon in one of three Top 14 games on Sunday.
Lock Rory Arnold says the timing was right to leave the Bumbies and ply his trade in the Top 14 with Toulouse next year.
Clermont Auvergne’s advantage at the top of the Top 14 table was cut to three points following Toulouse’s victory on Sunday.
Jerome Kaino will not be available until December after the Toulouse forward failed with an appeal against his five-match ban.
Freddie Burns should have been Bath’s match-winner but was distraught after failing to touch down under the posts.
Leinster will have to see off three former champions if they are to retain their European Champions Cup title in 2018-19.