Shane Horgan was among Leinster's try-scorers
Leinster: (13) 30
Tries: Jackman, Gleeson, Horgan
Cons: Contepomi (3)
Pens: Contepomi (3)
Connacht: (21) 21
Tries: Flavin, Warwick
Pens: Warwick (3)
Leinster overcame a sluggish start and a determined Connacht side to move back to the top of the Magners League table with a 30-21 victory at Donnybrook.
Three penalties and a try from Paul Warwick plus a Adrian Flavin try helped Connacht lead 21-10 at half-time with Bernard Jackman scoring a Leinster try.
However, Leinster hit 17 points without reply after half-time with Keith Gleeson and Shane Horgan scoring tries.
Felipe Contepomi's 100 per cent kicking return yielded 15 points in the game.
Helped by the return of Girvan Dempsey, Gordon D'Arcy, Horgan, Denis Hickie and Trevor Hogan from Six Nations duty, Leinster looked well placed to make a winning return to league action.
However, the visitors went 13 points to the good after only 14 minutes' play.
Warwick landed his first two penalties and sandwiched in between was a peach of a try in the left corner from Flavin who touched down after a superb rolling maul.
Just when they needed it, Leinster struck for their opening try when former Connacht favourite Bernard Jackman darted over after some neat interplay between Contepomi, Hickie and Gleeson.
Contepomi converted the try but Connacht still took a 21-10 lead into the break after Warwick scored his try before the Leinster fly-half replied with a penalty.
Connacht flanker Matt Lacey saw yellow in injury-time and Leinster, despite some excellent defence from the westerners, took over in the second half.
The 14 men of Connacht managed to keep Leinster out before Lacey's return, but Chris Whitaker and Contempomi combined to put Gleeson tearing over in the 53rd-minute.
Contepomi then delivered a cross-field kick out to the right for Horgan to gather, above two defenders, and swoop for Leinster's third try.
Contepomi's conversion nosed the hosts into a 27-21 lead and his 67th-minute penalty took what would have been a deserved bonus point away from Connacht.
Leinster: Dempsey, Horgan, Lewis, AN Other, Hickie, AN Other, Whitaker, Wright, Jackman, Green, Hogan, O'Kelly, Keogh, Gleeson, Heaslip.
Replacements: Blaney, Corrigan/Pala'amo, Finegan, Jowitt, Easterby, AN Other, Fitzgerald/Kearney.
Connacht: Duffy, Yapp, Riordan, Williams, McPhillips, Warwick, Keane, Wilkinson, Flavin, Knoop, Gannon, Farley (c), Muldoon, Ofisa, Rigney.
Replacements:Fogarty, Hogan, Swift, Lacey, McHugh, Hearty, Slemen.