WASPS have worked hard to return to the top tier of European club rugby, but their life in this season’s Champions Cup already looks under severe threat after they suffered a second defeat in a row this afternoon, losing 23-16 to Harlequins.

Having grasped a losing bonus point at Leinster last weekend, they needed a home victory against Harlequins to make it feel more substantial than scraps off the table.

But the Londoners, a different animal to what they were a month or so ago, were worthy winners at Adams Park.

Their fast-moving game stretched Wasps’ defence whenever it clicked into groove, but it was the pack that won this match for them, with the decisive score being a penalty try after they had twice sent Wasps back-peddling over their own line.

In the end Dai Young’s team had to dig in to protect a second losing bonus point, but they play Castres home and away next and they will probably have to win both games to stay in this competition past the pool stages.

It’s a big ask, and while Wasps’ are on the cusp of being a top team, they’re not there yet; this Champions Cup season might have to be chalked off as experience.

Losing at home is always costly, but Wasps had two glorious chances to work the scoreboard early when Marland Yarde’s fumble from kick off followed by a penalty kicked to the corner handed them two fine attacking platforms in the opening five minutes.

But the first attack ended when their pack splintered horribly at scrum time, and their big guns were silenced again when they tried to drive over from the line-out.

Having squandered two promising positions, Wasps duly fell behind after 13 minutes when Nick Evans took his first chance off the tee.

The hosts might have replied with their second penalty after 13 minutes, but again they kicked for the corner and again got nothing from it, and it wasn’t until the 19th minute that they finally got on the scoreboard as Andy Goode made it third time lucky when he went for posts.

But they gifted the initiative back seconds later by coughing up another penalty, and after Evans had done the honours off the tee, the visitors really began to turn the screw.

More than once their pace and handling sliced Wasps open and it would have brought the game’s first try after 25 minutes were it not for two magnificent tackles from Alapati Leiua.

First he swooped on Dave Ward after the hooker had slipped past Andrea Masi and then in the same play, he came to Wasps’ rescue again when he wrapped Matt Hopper up on the line to prevent him grounding the ball.

In the end, Quins trudged back to their half empty-handed and Leiua’s interventions appeared even more telling on half an hour when Joe Simpson scored the sort of try that makes him such a threat.

Quins back row forward Luke Wallace had possession and was powering out of his 22. The diminutive Simpson was in his way, and succeeded in slowing him down before suddenly peeling away with the ball in two hands.

A posse of forwards crowded the turf he was running into, but he was through them before they could react to slide over in the corner.

Goode’s touchline conversion made it 10-6, but it was a slightly fortuitous lead and three minutes from the break reality bit when Quins zipped the ball through the hands superbly to send Charlie Matthews over.

A penalty each way moved the score to 16-13 before Goode stuck again off the tee to level it up with a quarter of the match remaining.

But throughout the match there was a feeling that Wasps were hanging on by their fingertips, and the pressure finally told with a set of scrums in the corner 15 minutes from time.

Each one sent the black and golds into reverse gear, and after they’d infringed once too often the inevitable penalty try came.

Evans converted for 23-16, and it would have been even worse for Wasps had the Quins fly half knocked over a penalty with the last act of the game to deny them even the scant consolation of a bonus point.