Connacht scored four tries but still lost out to Leinster, who rallied from 17 points down to triumph in dramatic circumstances.
Leinster produced a sensational second-half comeback as Andrew Porter's try in added time clinched a thrilling 33-29 victory over Connacht on Saturday.
The reigning European champions looked in danger of losing for just the second time in Pro14 action this season when they trailed 29-12 midway through the second half at the RDS.
Connacht cut loose to run in four tries against a side who top the table in Conference B, fly-half Jack Carty scoring one of them to go alongside his nine-point haul with the boot.
However, Leinster stormed back to win in dramatic circumstances in Dublin. Ross Byrne converted tries from Sean Cronin and Dan Leavy before Porter completed the turnaround by barging his way over from close range.
Meanwhile, Conference A leaders Glasgow Warriors slipped up against Edinburgh in the first of three meetings in this season's 1872 Cup.
Duhan van der Merwe crossed twice - both after intercepting passes - as Edinburgh ran out 23-7 victors at Murrayfield, with the rivals due to meet again at Scotstoun Stadium on December 29.
Richard Cockerill's side have now won seven on the spin at home in the league this season, with their latest triumph lifting them up fourth in Conference B.
On a day when derby fixtures took centre stage in the competition, Ospreys ended a run of 10 successive defeats by beating Scarlets 19-12 at the Liberty Stadium.
Luke Morgan scored the only try of the game in the all-Welsh battle, the winger hacking a loose pass through with his boot before winning the race to the loose ball.
Sam Davies was successful with the conversion as he finished with a personal haul of 14 points, including two drop goals that gave the hosts breathing space in the second half.
