Humphreys kicked three penalties and converted his own try with 11 minutes remaining as Ulster edged a fast and furious encounter 16-11 in south-east Belfast.

The crucial score came as a result of replacement full back Adam D’Arcy’s brilliant break from deep in his own territory as Clermont committed their one major defensive error of the encounter.

D’Arcy spilt the onrushing defensive line to take play to the edge of the Clermont 22 before supplying the scoring pass to his fly-half, with Humphreys having covered a huge amount of ground to remain in support.

Humphreys stayed cool to add the testing conversion from wide on the left and, despite a frantic finish, Ulster held on to boost their hopes of matching last season’s qualification for the quarter finals.

Clermont will argue that they were hard done by having led for all bar the final few moments and it was they who opened the scoring with the game just seven minutes old.

The first half proved to be a scrappy affair, with neither side managing to hold on to possession for long enough to cause the opposition continued difficulties, but the visitors deserved their 11-6 lead at the break.

Clermont, who sit second in the Top 14 just a point behind Toulouse, claimed the half’s solitary try through Fijian U20 wing Noa Nakaitaci after the youngster saw off Paul Marshall’s desperate tackle.

But while it was Nakaitaci left celebrating the score on his Heineken Cup debut, the real inspiration was Wales and Lions star Lee Byrne. The ex Osprey ghosted through on the edge of the 22 to give his new side’s Heineken hopes an early boost.

With the normally reliable boot of Morgan Parra failing to add the extras and an earlier penalty attempt, David Skrela took over the duties from the tee and landed a 17th-minute effort that cancelled out Humphreys’ first successful strike of the afternoon.

Skrela slotted a second shot at goal to hand Clermont an eight-point advantage just two minutes before the break but Humphreys cut the gap to five on the stroke of half-time.

The game came alive in the second period although the scoreboard was rarely troubled. Humphreys reduced the deficit even further 10 minutes in before his most high-profile intervention late on.

Brock James could have kept Clermont on track for a vital victory but he twice missed the target after replacing Skrela and Clermont were left to ponder what might have been.