Down 28-7 at the interval, Ulster 'A' rallied after the restart, but Leinster 'A' still ran out easy winners of this Celtic Cup game at Malone.
Ulster took the lead after 15 minutes when James Hume charged over from 10 metres out but the Leinster pack then took over and, with four tries, the visitors had earned the bonus point by half-time.
Leinster made it 33-7 with a fine Michael Silvester try but after 67 minutes Ulster had brought it back to 36-28 and were hoping for at least two bonus points, if not victory.
However, Leinster had other ideas and added a Dan Sheehan try in the 76th minute to put the issue beyond doubt.
Ulster's consolation was a losing bonus point for their four tries.
Ulster 'A' - P Nelson; A Sexton, J Owens, J Hume, I Hughes, J McPhilips, J Stewart; S Van der Merwe, P Cromie, R Ah You; P Browne, A Thompson; C Montgomery, C Henry (capt), G Jones. Reps: P McGookin, M Rea, P Cooper, M Rea, B Houston, M Crowe, G Curtis, M Stronge.
Leinster 'A' - H Keenan; M Silvester, C O'Brien, T Daly (capt), J Kelly; H Byrne, P Patterson; E Byrne, R Kelleher, V Abdaladze; R Molony, J Dunne; O Dowling, S Penny, C Doris. Reps: D Sheehan, G Coyne, J Aungier, R Foley, R Waters, H O'Sullivan, D Hankshaw, L Turner.
REF - J Neville.