Nick Evans produced a match-winning performance at the Twickenham Stoop as Harlequins beat London rivals Wasps 32-22 to reach the semi-finals of the Amlin Challenge Cup.
The New Zealand fly-half kicked five penalties, two conversions and a sweet drop-goal in a faultless kicking display as Harlequins succeeded at keeping a spirited Wasps side at arm's length.
Harlequins had roared into a 14-0 lead with tries from Danny Care and Maurie Fa'asavalu before some of the crowd had even taken their seats. Wasps responded well with tries from Seb Jewell, Tom Lindsay and Richard Haughton but Evans' golden boot guided Harlequins to victory.
Harlequins, who won this tournament in 2001 and 2004, will face either Munster or Brive in the semi-finals. For Wasps, defeat effectively signals the end of their season. Winning the Amlin Challenge Cup was their only realistic route back into Heineken Cup rugby next season.
Harlequins were without prop Joe Marler, who was suspended after being sent off against Leicester, while captain Chris Robshaw missed out with a deep cut to his knee. Nick Easter took over as captain and Ceri Jones deputised at loose-head while Wasps were forced into a late change with Jewell promoted to start in place of Ben Jacobs at outside centre.
Harlequins, who had registered two wins and a draw from their three previous meetings with Wasps this season, started like a steam train, powering through some flimsy Wasps defence and into a 14-0 lead inside just six minutes.
Care got the ball rolling after 90 seconds when he stole away from the base of an unguarded ruck on the Wasps 22 and scampered under the posts, leaving Evans with a simple conversion.
When Simon Shaw spilled the ball on half-way, Care launched a blistering counter-attack before Jordan Turner-Hall crashed onto a pass from George Lowe and into the Wasps 22. Will Skinner took the ball on and Fa'asavalu careered through three would-be tacklers to score Harlequins' second try from close range, allowing Evans another routine conversion.
A rout was on the cards. Wasps could not keep possession and Quins seemed in the mood to make them pay. Easter collected a cross-kick from Evans and slipped a one-handed off-load to Ugo Monye but Wasps snatched the turnover and Richard Haughton streaked clear.
The England Saxons wing had no support and hacked aimlessly ahead – but it gave Wasps the chance to reorganise and, with Serge Betsen in ferocious form, they steadied the ship. Riki Flutey and Jewell were asking questions in midfield and it was the 23-year-old latecomer who crashed over the line for the first Wasps try after Joe Simpson had cut open the Quins defence.
Jewell's try, confirmed by the television official and converted by Walder, gave Wasps a toe-hold in a game that had been running away from them. It could have been better still. David Lemi beat three defenders with a jinking run and then collected a flat pass from Dave Walder but was tackled into touch just short of the line by opposite number Gonzalo Camacho.
Walder slotted a drop-goal to draw Wasps within four points but Harlequins resumed control by the interval, with Evans landing three penalties to open a 23-10 lead. Evans slotted another after the restart before Wasps won a penalty 40 metres out and opted to go for touch. It proved a worthy gamble.
Lemi's replacement Christian Wade almost carved his way through the Harlequins line but Wasps drove on, attacking at close quarters until Lindsay barrelled over for the try. Evans landed a fifth-consecutive penalty to edge Harlequins two scores clear again but Wasps refused to go down without a fight.
Lindsay was held up over the line as he drove in search of his second try of the night. When Andy Powell then attacked the blindside he should have passed to Simpson for a certain try but he was swallowed up by the Harlequins defence.
Care tried to relieve the pressure for Quins with a jinking run but, with seven minutes remaining, Wasps created the opening after a break from the impressive Flutey.
The England centre combined with Jewell and Mark van Gisbergen before Wasps moved the ball wide right and Haughton scored in the corner. Walder missed the conversion and Harlequins marched upfield and sealed the game with a drop-goal from the imperious Evans.