Harlequins (13) 19
Tries: Turner-Hall Cons: Evans Pens: Evans 3 Drop-goal: Evans
Stade Francais (14) 17
Tries: Oelschig Pens: Oelschig 3 Drop-goal: Hernandez
Evans landed the match-winning kick five minutes into injury time
A last-gasp drop-goal from Nick Evans secured a dramatic Heineken Cup victory for Harlequins against Stade Francais.
A try and two Noel Oelschig penalties put Stade 11-3 ahead but Jordan Turner-Hall's try and five points from Evans briefly put Quins back in front.
A third Oelschig penalty gave Stade a 14-13 half-time lead, only for Evans to again nudge Quins back in front.
Juan Martin Hernandez's drop-goal looked to have secured a Stade win but Evans struck deep into injury time.
Quins hammered away in the closing stages with an attack which went through 30 phases and saw them come close to scoring a try several times.
As the clock ticked well into the fifth minute of injury time the ball was passed back to Evans and, with the last kick of the match, the New Zealander scudded a low drop-goal between the posts.
It barely made it over the bar and had to be referred to the television match official, but he duly awarded it to send the Harlequins players and their fans delirious with joy.
The result means Harlequins top Pool Four by six points from the French side with two games remaining.
The first encounter between the two sides saw Harlequins stage a smash and grab raid in front of over 76,000 spectators at the Stade de France last Saturday.
For all the recent improvements at a packed Twickenham Stoop the return was in decidedly more prosaic surroundings, with heavy rain turning the pitch into a quagmire and making handling very difficult.
The gloomy conditions were at least illuminated by the respective strips with Harlequins' light blue, magenta, chocolate and French grey quartered shirt for once outshone by Stade's pink and blue tie-dye effort.
Quins took an early lead when Evans, Dan Carter's understudy for the All Blacks before heading to London, bisected the posts, but Stade rapidly hit back with a penalty of their own from Oelschig.
The scrum-half then sniped over from a five-metre scrum to score the first try of the match and although he missed the conversion a second penalty gave the fired-up visitors an 11-3 lead after 11 minutes.
Evans trimmed the gap with a second penalty midway through the half and Quins took the lead after 28 minutes when Turner-Hall crossed untouched under the posts.
Turner-Hall scored a superb first-half try for Harlequins
Harlequins won quick ball off the top of a line-out and when they shipped it into midfield Turner-Hall cut a stiletto line to scissor with Evans before racing over, with Evans adding the extras to put the Londoners in front.
The lead only lasted seven minutes before former South Africa Under-21 international Oelschig kicked the visitors back in front and they led 14-13 at half-time.
Quins twice spurned kickable penalties in the first half and subsequently failed to score but boss Dean Richards must have had a word during the interval because when they were awarded a penalty in the 48th minute they never looked like taking it quickly.
Evans stepped up to kick them back into the lead and when Argentina star Hernandez fell short with a long-range effort for the French side it started to look like it might be Harlequins' night.
Will Skinner was denied a try by the arm of Juan Leguizamon and Ugo Monye's footballing skills deserted him when he raced onto Evans's astute chip, and the near misses nearly came back to haunt the hosts.
Hernandez had produced a decidedly mixed display and had already missed a couple of drop-goal attempts but with eight minutes left he drilled the ball between the posts to put Stade Francais back in front once more.
It looked as though the Parisians were going to head back across the channel as Group Four leaders, but in a nerve-shredding finale Evans stepped up to snatch an epic victory for Harlequins.
Harlequins: Brown; T Williams, Tiesi, Turner-Hall, Monye; N Evans, Care; Jones, Fuga, Ross, Percival, J Evans, Robshaw, Skinner, Easter.
Replacements: Barry for Tiesi (70), Robson for Percival (57).
Not Used: Brooker, Lambert, Guest, Gomarsall, Malone.
Stade Francais: Hernandez; Gasnier, Glas, Liebenberg, Mi Bergamasco; Bousses, Oelschig; Roncero, Szarzewski, Marconnet, Marchois, Vigouroux, Parisse, Ma Bergamasco,
Replacements: Bastareaud for Bousses (59), Attoub for Roncero (65), Blin for Szarzewski (59), Rabadan for Vigouroux (50).
Not Used: Messina, Albouy, Camara.
Ref: Nigel Owens (WRFU).