Racing, Leinster make winning rugby starts in Europe
Racing 92 scratched out a 22-18 victory over Leicester in the opening round of European Champions Cup fixtures on Saturday, while twice former winners Leinster defeated Montpellier 24-17.
Racing, beaten finalists in 2016, handed a debut to South Africa fly-half Pat Lambie as the Springbok replaced the injured Juan Imhoff after just six minutes at the Stade Yves du Manoir.
Luke Hamilton notched an early try for Leicester, the 2001 and 2002 champions, in the Pool 4 clash but hosts Racing stormed back with three quick tries from Leone Nakarawa, Bernard Le Roux and Teddy Thomas.
England wing Jonny May touched down before the break to trim Racing's lead to 19-15, with Maxime Machenaud and George Ford exchanging penalties in a cagey second half.
"Victory is a huge satisfaction because in this high-level competition you have a lot of pressure on your shoulders when your first match is at home," Racing coach Laurent Labit said.
Racing were camped deep in Tigers territory in the dying seconds but Virimi Vakatawa couldn't convert a late opportunity as the French club missed out on an attacking bonus point.
"It's a precious point that we weren't able to go and get in the second half because of a lack of control at some moments, and a lack of patience at others," added Labit.
Irish province Leinster ran in four tries through Joey Carbery, Josh van der Flier, Robbie Henshaw and Tom Daly to claim a bonus-point win at home to Top 14 high-flyers Montpellier in Pool 3.
Fijian Nemani Nadolo crossed the whitewash twice in defeat for Montpellier, without former All Blacks fly-half Aaron Cruden due to injury, as they settled for a losing bonus point.
La Rochelle, the surprise regular-season table-toppers in France last campaign, earned a 34-27 bonus-point win at Harlequins on their competition debut.
Kiwi hooker Hikairo Forbes' third-minute try laid the blueprint for a maiden La Rochelle triumph as Geoffrey Doumayrou bagged a pair of tries either side of Dany Priso touching down.
Bath shut out Italians Treviso 23-0 in Pool 5 with former Scarlets fly-half Josh Lewis kicking 13 points to go along with scores from Zach Mercer and Aled Brew.
Reigning champions Saracens kick off the defence of their title on Sunday at English Premiership rivals Northampton, while last season's runners-up Clermont travel to Ospreys in a gruelling Pool 2.