Leo Cullen's side scored 10 tries
Leinster enjoyed a comfortable night's work in the Guinness Pro 12 as they ran in 10 tries to brush aside Zebre by a 70-6 scoreline at the RDS Arena.
Rory O'Loughlin scored a hat-trick of tries for Leo Cullen's side in a match in which they earned a bonus point by half time. The score at the break was 35-6.
Ireland international youngster Garry Ringrose also delivered a pair of tries.
Leinster's Johnny Sexton ©INPHO/Dan Sheridan
Also on the list of Leinster try scorers were Sean O'Brien, who scored the first one for the home side, while Hayden Triggs, Cian Healy and Jamie Heaslip also scored.
Ireland fly half Jonny Sexton was also marking his return to action after being sidelined by injury.
He managed six conversions, while Ross Byrne added four more.
Leinster's Sean O'Brien and Matteo Pratichetti of Zebre ©INPHO/Ryan Byrne
The bonus point win lifts Leinster to level on points with Pro 12 leaders Munster in the table, although Leinster have played a game more.
Ulster, however, fell to a narrow defeat at Scarlets.
In a tight fixture in Wales, the home side edged it by a 16-13 scorline.
Ulster's Jacob Stockdale scores his side's first try ©INPHO/Camersport/Kevin Barnes
Ulster's sole try came via Jacob Stockdale in a first half which left the Irish province leading 13-6.
But Scarlets fought back in the second half as a penalty try proved crucial in swinging the game in their favour.
Ulster's Stuart McCloskey is tackled by Steffan Evans of Scarlets ©INPHO/Camersport/Kevin Barnes
By way of consolation, Ulster left Parc y Scarlets with a losing bonus point.
Newport Gwent Dragons beat Benetton Treviso 26-8 in the night's other game.