The 26-year-old winger, who featured for Ireland in their final RBS 6 Nations game with England, slipped past the Saints defence to score after 32 minutes and give his side the lead but they failed to capitalise and Saints' Lee Dickson’s wonderful second-half try proved decisive.

At stadium:mk Saints’ Tongan prop Soane Tonga’uiha barged his way through the visitors’ back line after two minutes, with Stephen Myer adding the extras.

But despite the early setback Ulster stayed strong and two penalties in eight minutes from Ian Humphreys brought them within a point of the hosts.

With the momentum moving in their favour Trimble picked his time to strike, bursting into space created by Simon Danielli and going over to give Humphreys an easy conversion and hand the visitors a 10-13 lead at the break.

In the second half it took Saints just nine minutes to draw level, Myer kicking a solid penalty to leave the game on a knife-edge.

As the temperatures and tempers soared England team-mates Ben Foden and Chris Ashton combined to start a flowing counter-attack down the left wing, laying it off to Jon Clarke and finally finding Dickson to score.

Myer kicked to take the lead to seven points with 24 minutes remaining, and after Ulster’s Adam D’Arcy wasted a golden opportunity Myer was on hand again to kick his fifth of the game and seal Saints’ progress.