It was a performance riddled with mistakes, so many of them elementary, but the side's reaction to adversity in the second-half, when coming from 13-0 down to claim the lead and hold out in the face of considerable pressure, was impressive.

It remains to be seen who they face in the quarter-final but a trip down the M1 to face rivals Leinster, who take on Wasps in Coventry tomorrow, is one possibility. All that can wait. For now, the fact that they are in the hat is enough.

The task here was surprisingly straightforward amid the usual head wreck of final round permutations: claim just a losing or a try-scoring bonus point and they would be through. Fail and the law of averages were still well in their favour.

Still, better not to rely on others, eh?

Though his side was already eliminated from the reckoning, Leicester boss Geordan Murphy had opted to name a strong XV for the visit of the Irish province who were themselves boosted by a handful of heartening injury updates this week.

Second row Iain Henderson made a surprising return while out-half Billy Burns passed a fitness test on a leg injured during last week's dramatic defeat of Racing 92 in Belfast. Scrum-half John Cooney (back) was deemed fit enough to make the bench.

All positive then but what followed was a 40-minute horror show.

Everything Ulster could do wrong in that opening period they did. They knocked balls on, coughed up lineouts in the opposition 22, suffered in the scrum and failed to resource rucks. Ultimately, they allowed a game devoid of structure to develop and paid for it.

Leicester, no great shakes themselves and guilty of looking more than the odd gift horse in the mouth, eventually made the visitors pay when George Ford landed the game's first score after 22 minutes from a penalty after Marty Moore went blatantly off his feet at a ruck.

Far worse was to follow just before the break.

Leicester laid the foundation for the game's opening try with a sustained passage of pressure in and around the Ulster 22 before a lovely grubber kick from Ford allowed centre Matt Toomua to outflank the defensive line and touch down.

Ford's conversion left it 10-0 at the interval and a second penalty from the England international shortly after the restart stretched that to 13 before Cooney finally came off the bench to mould some shape and direction into the Irish side's game.

Less than ten minutes later and Ulster were finally clicking when, at the fifth time of asking, they managed to win their own lineout inside the home 22 and maintain control long enough for Moore to fall over the line for a try that would be converted by Cooney.

Five minutes later and there came a second.

Burns, clearly not at his best for most of the tie, provided the opening with a delicious chip kick over the defensive line and young winger Robert Baloucoune sped in to profit from a decent bounce of the ball and make for the posts.

Another two points from Cooney and Ulster were ahead, 14-13.

Not the performance head coach Dan McFarland was hoping for on arrival in England but the result was everything. Ulster, after too many years of poor results on the field and no little negativity off it, are back among Europe's elite.

Leicester Tigers: J Holmes, J May, M Tuilagi, M To'omua, J Olowfela; G Ford, B Youngs; G Bateman, J Kerr, D Cole; M Fitzgerald, G Kitchener; M Williams, B O'Connor, S Kalafamoni. Replacements: W Evans for O'Connor (41); H Wells for Kitchener (59), J Heyes for Cole, F Gigena for Bateman and R McMillan for Kerr (all 65); A Aspland-Robinson for Olowolefa and B White for Youngs (bth 71).

Ulster: L Ludik; R Baloucoune, W Addison, S McCloskey, J Stockdale; B Burns, D Shanahan; E O'Sullivan, R Best, M Moore; I Henderson, K Treadwell; S Reidy, J Murphy, M Coetzee. Replacements: N Timoney for Coetzee (34); A Warwick for O'Sullivan and J Cooney for Kitchener (both 49); R Herring for Best and A O'Connor for Treadwell (both 65); M Lowry for Burns (70); R Kane for Moore (77).

Referee: A Ruiz (France).