A stoppage-time interception try from Shane Roiser denied Harlequins a vital bonus point at Loftus Road on Friday as Wasps ran out winners 16-6.

Despite fly-half David Slemen failing with four penalties and three drop-goal attempts, Quins looked set to pick up at least one point from a truly dreadful game.

But Roiser moved up to collect Will Greenwood's pass on halfway and sprinted home to keep Wasps' Heineken Cup challenge alive and leave Quins still two points ahead of basement outfit Leeds, who visit the Stoop in a make-or-break encounter next Friday.

In their perilous position, Quins preferred to keep invention to a minimum and rarely offered a serious attacking threat.

Any territorial gains they did make were a result of Wasps errors, such as Josh Lewsey punting a mammoth kick dead from inside his own 22.

By far the worst home culprit though was hooker Trevor Leota, who through a variety of means conspired to lose 13 out of 22 line-outs on his own throw.

Given such a dismal effort, it was something of a shock that the visitors weren't in front at the break, but Slemen was equally profligate with his goalkicking.

The stand-in stand-off did give his side the lead after nine minutes but that advantage was cancelled out by Kenny Logan's long-range reply.

Alex King then landed a drop goal after Simon Shaw had fronted a powerful Wasps forward drive and with Slemen failing to emulate the Wasps man in stoppage time, the home side trooped in with a three point lead.

It didn't improve much after the break either.

Slemen tried his luck again with a drop-goal shot five minutes after the restart but to the surprise of absolutely no-one it sailed wide of the uprights.

To be fair to the Quins man, a fairly blustery wind was blowing across the ground but his efforts seemed to sum up the pitiful nature of the evening.

However, if that was bad, worse was to follow. Having dragged Wasps across the field thanks to a Matt Moore burst, Quins moved the ball right where they created a four-man overlap.

Greenwood intelligently chipped for the corner, where Quins replacement Tony Diprose and team-mate Ben Gollings awaited the ball with not a Wasps player in sight.

But, in their combined eagerness to score, the pair somehow managed to knock the ball on inside the Wasps in-goal area.

Quite what Quins chief executive Mark Evans made of this was uncertain but the home supporters could barely suppress their laughter.

Leota finally found Ian Jones with a line-out throw only for the former All Black's knock down to bounce into Ace Tiatia arms allowing the flanker to launch a Quins counter.

However, the Samoan's next throw was wayward, forcing the Wasps pack to infringe as they attempted to stem the visitors' forward drive.

From 20 metres, Slemen found the target to pull his team level, although within a minute he drifted an ambitious drop-goal attempt wide.

With eight minutes remaining, Paul Sampson was thrown on for Wasps sporting a 'Freddie Ljungberg' hairstyle to add a bit of colour to the evening.

The England international inspired the home side to one last effort and after Leota had again literally thrown away possession, the Wasps forwards scrambled it back and King landed his second drop goal.

Slemen had a chance to level almost immediately but failed from the corner and then cruelly, two minutes into stoppage time, Roiser spotted Greenwood's long pass, intercepted to score and with the last kick King snatched away Quins' bonus point.

Teams:

Wasps: Lewsey, Roiser, Abbott, Denney, Logan, A. King, Wood, Dowd, Leota, W. Green, Shaw, Jones, Lock, Worsley, Dallaglio.

Replacements: Sampson for Denney (73), Friday for Wood (70).

Not Used: Leek, Barratt, Jenkins, Beardshaw, Mackenzie.

Tries: Roiser.

Cons: A. King.

Pens: Logan.

Drop Goals: A. King 2.

Harlequins: Gollings, Jewell, Greenwood, Bell, Moore, D. Slemen, J. Powell, Leonard, Wood, Olver, Morgan, Codling, White-Cooper, Tiatia, Winters.

Replacements: Diprose for White-Cooper (40).

Not Used: Fuga, Starr, Davison, Duncombe, Mapletoft, Greenstock.

Pens: D. Slemen 2.

Att: 8,388

Ref: Steve Lander (RFU).