Barry Daly scored a try on his debut as Leinster moved to the top of the Pro12 table with a 24-13 victory over Connacht, and Ospreys are second after claiming a bonus-point derby win over Newport Gwent Dragons.
Leo Cullen's men gained revenge for a defeat to Connacht in the Pro12 final back in May, with wings Adam Byrne and Daly touching down in the second half at the RDS Arena on Saturday.
Captain Isa Nacewa scored 14 points from the tee as Leinster made it six wins out of seven in the competition to take over at the summit, with Shane Delahunt's late try no more than a consolation for a Connacht side that had won their previous four matches.
Leinster are now unbeaten in 19 home matches and are level on points with the Ospreys and Glasgow Warriors.
Teenage wing Keelan Giles made it eight tries in his last four games by claiming a double in the Ospreys' 35-17 win over rivals Newport.
The struggling Dragons have now lost their last 10 encounters with Ospreys after 18-year-old Giles crossed twice in the second half, with Tom Habberfield, Wales international Scott Baldwin and Brendan Leonard also dotting down.
Matthew Screech and Pat Howard scored late tries for the Dragons, but the damage had already been done and they have only one win to their name after seven Pro12 matches.