It was the province’s first outing since the tragic loss of the young centre, who died alongside his father Noel and brother Graham in an accident on their Hillsborough farm in Down two weeks ago.
Ulster were desperate to begin their heeling process on the pitch but wore Spence’s initials on their jerseys — something they will continue for the rest of the season.
Michael Allen and Nick Williams grabbed first-half tries before Tommy Bowe, Williams, Jared Payne and Andrew Trimble completed the rout in the second half.
Darren Cave spilled the ball straight from the kick-off and the hosts quickly took the lead, thanks to the boot of Jason Tovey.
Cardiff continued to threaten and Sam Warburton came close but knocked on with the line beckoning after a Tom James grubber.
Tovey stretched Cardiff’s lead further on eight minutes but Paddy Jackson quickly responded. With a dominant scrum causing Cardiff all manner of problems at the set-piece, Ulster began to establish a foothold and they soon took the lead.
Following several resets at a five-metre scrum, in which Cardiff were lucky to escape without conceding a penalty try, the ball was spread to Allen, who twisted over. Jackson slotted the extras but Cardiff hit back with the boot of Tovey to regain the lead.
However, it did not last long with Paul Marshall’s superb blindside break making the inroads for Williams’ try.
Jackson was again on target and Ulster entered the break leading 17-9.
Gareth Davies, on for Tovey who suffered a suspected broken leg just before half-time, cut the deficit within minutes of the restart. But Ulster struck with Bowe’s first try back in Ulster colours. A sublime slip pass from Jackson created the opening and the Irish flyer skipped past James to score.
And they put the result beyond doubt with two tries in as many minutes. Jared Payne grabbed the first after collecting his own chip to race clear and wrap up the bonus point. Then Bowe continued the rout with his second — to take his Celtic rugby tally to 48. Cardiff nicked a consolation try when Harry Robinson latched on to James’ flick pass. Anscombe’s men put an end to any hope of a comeback as Williams crossed for his second, before Trimble ended the scoring.
Cardiff Blues scorers: Try: H Robinson; Con: G Davies; Pens: J Tovey (3), G Davies.
Ulster scorers: Tries: M Allen, N Williams, T Bowe (2), J Payne, A Trimble; Cons: P Jackson (5); Pens: P Jackson
CARDIFF BLUES: D Fish; H Robinson, D Hewitt, J Roberts, T James; J Tovey (G Davies 36), L Williams; N Trevett (C Ma’afu 46), A Kyriacou (R Williams 53), T Filise, B Davies, J Down (L Reed 46), R Copeland (R Watts-Jones 53), S Warburton (capt), A Pretorious.
ULSTER: J Payne; T Bowe (C Gilroy 63), M Allen (P Wallace 18), D Cave, A Trimble; P Jackson, P Marshall (M Heaney 67); T Court (C Black 67), N Brady (R Herring 67), J Afoa (A Macklin 74), N McComb (L Stevenson 67), D Tuohy, I Henderson (M McComish 63), C Henry (capt), N Williams.