Exeter Chiefs' year-long unbeaten run at home came to an end as Leinster won a fiercely contested battle between the two front-runners in Pool 3 of the European Champions Cup.
Jack Conan's second-half try ultimately secured a deserved 18-8 victory for Leinster on Sunday, condemning Exeter to a first home loss in the Premiership or Champions Cup since they were beaten by Bordeaux-Begles on the corresponding weekend in 2016.
Leinster were dominant in the opening quarter and tries from Jack McGrath and Devin Toner were controversially chalked off before Jonathan Sexton went over in the corner to open the scoring with the Chiefs down to 14 men following the sin-binning of Harry Williams.
After Gareth Steenson and Sexton - with his only successful kick from three first-half attempts - had exchanged penalties, the English champions saw a spell of pressure late in the opening period go unrewarded.
James Short surged over to level things up after the break, but Leinster came on strong again and Isa Nacewa kicked them back in front before Conan's match-clinching score, which came after more than 40 phases of attack.
La Rochelle turned on the style once again, making it three wins out of three in Pool 1 with a 49-29 victory over Wasps that leaves the Premiership side in a position of peril.
Levani Botia and Vincent Rattez each went over twice as La Rochelle crossed six times. Wasps, who had Thomas Young and Juan de Jongh sin-binned in the first half, did at least claim a bonus point thanks to five tries of their own.
John Cooney kicked four penalties and played a key role in Jacob Stockdale's first-half try as Ulster beat Harlequins 17-5 on a snowy afternoon at Twickenham Stoop. Ulster now sit second in Pool 1, two points clear of Wasps, while Harlequins have just a solitary point and are staring at an early exit.
The much-anticipated Pool 2 clash between last year's finalists, Saracens and Clermont Auvergne, was postponed due to hazardous conditions on the approach roads to Allianz Park and in the immediate vicinity of the stadium.