Ulster put in an impressive showing to defeat the Sharks 24-21 in a result that seals a home quarter-final in the United Rugby Championship.
They now wait to discover whether a potential semi-final will be home or away, while the Sharks will hope the Scarlets and Leinster do them a huge favour.
Following a lively opening with plenty of open play from both sides, the first points fell to Ulster through a 16th-minute John Cooney penalty after the Sharks had been pinged for being offside.
10 minutes later and with Ulster beginning to get some momentum in the contest – in tandem with the Sharks beginning to make too many errors – the Irish province began to win a series of penalties and put one into the corner.
They moved the ball off the maul and though Stuart McCloskey was stifled in the midfield, the ball came back to the busy Billy Burns, who shifted it long and wide to Ethan McIlroy, giving the wing the chance to attack the try-line, draw the cover and throw an inside pass to the supporting Mike Lowry, who touched down.
It was no more than Ulster deserved and Cooney’s conversion ensured they had a 10-0 lead.
Though the Sharks continued to give the ball air, they were unable to score and came the nearest to breaking their duck when Curwin Bosch attempted a long-range penalty which went wide, preserving Ulster’s 10-point lead at the break.
That became 17-0 three minutes after the restart when McCloskey smashed through several defenders to score under the posts, allowing Cooney to convert.
The Sharks had to respond but were unable to do so until the hour mark when newly arrived substitute Ntuthuko Mchunu was driven over with Bosch converting.
Ulster, though, shut down any prospect of the visitors making further inroads and struck back immediately when Robert Baloucoune and Cooney combined to supply James Hume for the Irish province’s third try of the night. Cooney’s conversion put Ulster 24-7 ahead.
However, the Sharks came back with five minutes left through a Marius Louw try and Boeta Chamberlain conversion which closed it to 24-14, and Chamberlain converted again after Grant Williams surged through with two minutes remaining.
The hosts had lost their previous five home matches against Welsh opposition but never looked like losing a fixture in which they scored a remarkable 10 tries.
Callum Braley, Tomas Albornoz and Rhyno Smith all touched down twice for the home side, while Lorenzo Cannone, Michele Lamaro, Federico Ruzza and Giovanni Pettinelli were also on the scoresheet.
Smith racked up 29 points for the second week running – the most by any player in a URC match this season.
Cardiff had to make do with two tries from Rhys Carre and one for Max Llewellyn, along with six points from the boot of Rhys Priestland, as they slipped to 14th in the final table.
A pair of bonus points mean Toby Booth’s side are now two clear of the Scarlets at the top of the United Rugby Championship’s Welsh Shield, with the winner set to play in the top tier of European competition next season.
The Scarlets play the Stormers in Llanelli on Saturday and now need a win to overtake the Ospreys.
A hat-trick of tries from centre Cornal Hendricks along with scores from Madosh Tambwe, Chris Smith and Canan Moodie got the Bulls over the line. Smith also contributed eight points from the kicking tee.
The Ospreys scored four tries of their own to pick up two bonus points courtesy of Jac Morgan, Luke Morgan (2) and Sam Parry, with Gareth Anscombe kicking 11 points.