Nick Evans scored 14 points including a try on his return from a broken leg to send Harlequins into the European Challenge Cup final with a 30-6 thrashing of Grenoble.
An early Ben Botica penalty got Quins off to a good start at The Stoop and the home crowd really came to life after 12 minutes when Jamie Roberts went over.
Botica converted that try and the two sides traded penalties to give Harlequins a 13-6 lead at half-time.
Evans came on 10 minutes into the second half for his first appearance since breaking his leg against Gloucester in February – and made an almost immediate impact.
With the Grenoble defence standing firm, Evans unlocked it with a grubber kick and ran on to the ball himself to stretch the Quins lead.
He missed a penalty but made amends with a second one shortly afterwards as Quins edged closer to victory, and it was rubber-stamped as Danny Care’s grubber came back off the bottom of the post and was pounced upon by George Lowe.
Harlequins will face Montpellier or Newport Gwent Dragons in the final in Lyon on Friday 13 May.