Cardiff Blues – back in action after a three-week break – enjoyed a first half to forget as Ulster raced into an 18-0 lead courtesy of tries from Craig Gilroy and Louis Ludik.
Injuries to Cory Allen and Rhys Patchell in the opening ten minutes also forced a reshuffle for the region as they looked to keep the inspired Irish province at bay.
However, a second half fight-back from the Blues - as they opened up and played some thrilling rugby - had threatened a huge comeback.
Tom Isaacs and Alec Cuthbert crossed the whitewash as Blues rattled up 17 unanswered points and cut the lead to four points.
But a late charge from Ulster saw them secure a bonus point that keeps them towards the league summit while Blues turn their attention to the big Euro derby with Dragons during the Easter weekend.
Ulster, backed by a vociferous home crowd, flew out of the traps and went straight on the attack with back row Nick Williams and prop Callum Black combining in a physical and high tempo start.
A relentless opening three minutes saw Ulster menacingly keep the ball alive for 25 phases and eventually pressure told as tighthead Wiehahn Herbst broke into space and, when the ball was spread wide, Gilroy raced in to score to a thundering reception.
Ulster looked threatening with every wave of attack as a chip ahead from Darren Dave almost released Michael Allen but Cuthbert mopped up the danger during a torrid opening few minutes for the visitors.
Blues had already lost Allen to injury in the opening exchanges and it got worse as play was held up for several minutes after an ugly looking challenge on Patchell, with Williams yellow carded as a result.
On the resumption, Cuthbert attacked the line at speed as he cut in off his wing while Matthew Rees and Lou Reed also hurtled into contact as Blues looked to respond.
But it was Ulster that continued to build up the points with Ruan Pienaar slotting a penalty before a second home try as Ludik brushed off tackles out wide to dot down.
Errors were proving costly for Blues who were being repeatedly forced back by a hungry Ulster side that needed no second invitation to attack from all corners.
Pienaar added his second penalty of the night just after half hour mark before Blues finally took control of possession and produced a sustained period of pressure in the final minutes of the opening half.
Repeated penalties saw the home side lose Franco van Merwe to the sin bin and there were even appeals for a penalty try when a big lineout drive from the Cardiff forwards was illegally pulled down yards from the line.
However, for all the pressure there was no way through a well drilled defence as Ulster took an 18-0 lead into the dressing rooms at half-time.
The ever-reliable Pienaar kicked Ulster further ahead at the start of the second half before Anscombe recorded the first points of the night for Blues with a sweetly struck penalty kick.
It was to prove a turning point as suddenly Blues came alive and played some sensational attacking rugby.
Gavin Evans bounced Pienaar off and Cuthbert rolled out of tackles before the slick evasive feet of Lucas Amorosino blew Ulster apart and the Argentine fed Anscombe who in turn released Isaacs to race in.
Ulster looked rattled and Blues grabbed a second try with another well worked effort as Blues showed great composure and handling skills to free up space for Cuthbert to this time run down the same wing and score. Anscombe’s kick cut the lead to 21-17 with 16 minutes left.
Pienaar looked to steady any growing home nerves with his fourth penalty of the night, but the game was now finely balanced on a knife-edge going into the final stages.
Blues were showing great invention and keeping the ball alive as Kristian Dacey spotted a gap and broke away before feeding Manoa Vosawai and Macauley Cook. Evans then tore down the left wing as the visitors continued to play an entertaining and expansive game.
However, Ulster were not to be denied and after working field position grabbed a third score when a cross field kick from Paddy Jackson picked out a juggling Ludik to touch down.
And a bonus point try, that was harsh on Blues given the second half display, came when Ulster picked up a loose kick as the visitors looked to make something happen from deep and Paul Marshall completed the scoring.
Timeline:
03m Gilroy t Pienaar c 7-0
14m Pienaar p 10-0
18m Ludik t 15-0
31m Pienaar p 18-0
45m Pienaar p 21-0
46m Anscombe p 21-3
53m Isaacs t Anscombe c 21-10
63m Cuthbert t Anscombe c 21-17
69m Pienaar p 24-17
73m Ludik t 29-17
79m Marshall t Humphreys c 36-17
Cardiff Blues: 15 Rhys Patchell (Davies 7), 14 Alex Cuthbert, 13 Cory Allen (Isaacs 7), 12 Gavin Evans, 11 Lucas Amorosino, 10 Gareth Anscombe, 9 Lloyd Williams (Knoyle 71); 1 Sam Hobbs (Filise 75), 2 Matthew Rees (Dacey 59), 3 Adam Jones (Andrews 55), 4 Jarrad Hoeata (Cook 67), 5 Lou Reed, 6 Josh Turnbull, 7 Ellis Jenkins, 8 Josh Navidi (Vosawai 50)
Replacements: 16 Kristian Dacey, 17 Taufa’ao Filise, 18 Scott Andrews, 19 Macauley Cook, 20 Manoa Vosawai, 21 Tavis Knoyle, 22 Gareth Davies, 23 Tom Isaacs