Their 23-13 triumph at stadium:mk means Dylan Hartley’s men will host Perpignan in the semi-finals and ensured England have at least one representative in the final four this season.

Saints got off to a flying start and managed to score a try before an Ulsterman had had the ball safely in his hands. Ian Humphreys kicked-off, Courtney Lawes rose high and Lee Dickson’s box kick was knocked-on by Andrew Trimble.

Ulster were penalised at the first scrum and their former player Roger Wilson tapped and charged forward. The next phase was in front of the visitors’ posts and giant prop Soane Tonga’uiha simply popped out the front of it like a cork out of a champagne bottle to squirm his way over for a vital score.

Steve Myler had no problem with the conversion and the Saints had laid down a major marker within two minutes of the start.

But Ulster’s spirit was far from broken and Humphreys was bang on target with two inch perfect penalties to ensure that by the end of the first quarter they were back to within a point of the side that came through the Pool stages unbeaten.

They also managed to provide the Saints with a major scare when they worked Scottish international Simon Danielli over in the left corner only to find French referee Romain Poite calling him back for a forward pass.

After that early flurry of points the next scoring opportunity didn’t arrive until half-an-hour had expired and Myler was way off target. Then came the moment that brought the travelling army of 6,000 Ulstermen to their feet as their brave side edged ahead.

Ruan Pienaar kicked them down into the home 22 with a lengthy penalty kick and then the line-out worked perfectly to allow Danielli to come charging through the midfield. He got to within five metres before the recycled ball was given to his fellow wing Trimble who brushed aside two men to score at the posts.

Humphreys added the extras and all of a sudden the momentum was with the Magners League side, who were bidding to join fellow Irish province Leinster in the semi-finals. Saints hit back with a penalty from Myler on the stroke of half-time, but it was still the visitors who had their noses in front at the break.

Ulster had the advantage of the sun in their favour in the second half and both Humphreys and Pienaar tested Saints’ back three with some high balls, but they were up to the task and when Ulster failed to roll away in the tackle on 48 minutes Myler levelled the scores at 13-13 with his second penalty.

Saints were getting more of the possession and when Lawes stripped Ulster of a line-out it gave Myler the chance to test Adam D’Arcy’s defence with a high ball. The Aussie full back was up to the task and his relieving kick ended up in touch in the Saints half.

That was the cue for some magic from Saints’ English duo Ben Foden and Chris Ashton as they inter-passed up the left hand touchline before Jon Clarke joined in and sent scrum half Lee Dickson scampering over for a magnificent try. Myler converted and the English Premiership outfit were back in charge.

The Ulster reaction was fast and furious and two brilliant darts from Humphreys took them into the home 22 and when Saints conceded a penalty five metres out Pienaar took it quickly and helped to create an overlap on the left. But D’Arcy couldn’t hold onto Paddy Wallace’s pass and the ball never found the unmarked Danielli.

Having butchered that golden opportunity Ulster were made to pay when they conceded another penalty on their 10 metre line and Myler hit the target to stretch the lead to 10 points.

That’s how it ended to steer Saints into their third Heineken Cup semi-final and keep them on course to repeat their triumph of 2000.