The visitors took control right from the off, wing Ger O'Connor finishing expertly in the second minute. A sweet move concluded by right wing Adam Mangan for the second was followed by an immediate try from flanker Tom Cuddihy, converted by fullback Ronan Wallace.
The bonus-point was wrapped up by centre Peter Howard in just the twelfth minute, Wallace kicking the extras for a 24-0 lead, as Ulster struggled to cope with the momentum Leinster generated.
Ulster's only score, a penalty from their outhalf Jason Gribben in the 24th minute, was as close as they got to applying any sort of consistent pressure.
Centre Conor O'Brien carved out two tries in the 31st and 37th minutes as Wallace began to really hit his targets from the conversions. Prop Mike Russell also crossed the whitewash as a raft of replacements were made by both teams in the second period.
Ulster now face a trip to Musgrave Park to play Munster on Saturday. Kick off is at 1.00pm.