The Welsh region led 13-10 at the interval, thanks to the centre’s score, but Ulster replied with a devastating second-half performance, in which they racked up 27 unanswered points.
The Blues were dealt a blow in the build-up to the match with Alex Cuthbert withdrawing from the match due to his troublesome hamstring.
It was the Wales wing’s last chance to get game time ahead of the Lions tour but the Blues confirmed the decision was made as a precaution.
“He’s OK,” said director of rugby Phil Davies.
“There’s a lot at stake for him and he’s just come back from a hamstring injury and it was a bit sore and we decided it wasn’t worth the risk. It was just common sense.”
Despite Cuthbert’s absence the Blues got off to a flying start and it took them just four minutes to open the scoring. Lewis Jones broke clear and he found Hewitt in support to shock the hosts.
But Ulster hit back and Pienaar grabbed a try after Harry Robinson spilt the ball, with the South African’s conversion tying the scores.
Patchell and Pienaar exchanged further shots at goal as the Blues hung onto their slender lead going into the break.
But their advantage didn’t last long as Ulster hit the ground following the resumption of play. Within minutes of the restart Andrew Trimble powered over in the corner.
Pienaar kept the scoreboard ticking for the hosts and Trimble soon pounced for his second following a mix-up between Patchell and Robinson.
Ulster continued to dominate and after Hewitt was sent to the bin, Diack charged over beneath the posts at the death with Pienaar converting.
“We’ll be better for this experience,” added Davies when reflecting on a disappointing season.
“It’s been painful at times but you go through it and we’ll keep going forward.
“It’s been disappointing results-wise but the progress we’ve made has been phenomenal. When I turned up last May we’d lost around 15 players and it was really a rebuilding period and we feel we’ve got a strong platform to move forward.
“We have quality with this young group but with that comes inexperience so they will learn lessons from this year and with Gethin Jenkins and Matthew Rees coming in I think we’ll be a more progressive outfit and hopefully produce the results.”
