Andy Goode's injury-time conversion came back off the post to deny London Wasps victory over Harlequins, who triumphed 16-15.
The first half proved to be a scrappy affair as two normally free-flowing teams were unable to hold onto the ball for any sustained period.
Wasps did find their way over the try-line through Joe Launchbury and Andy Goode added a conversion and a penalty as they led 10-3 at the break, but genuine chances were at a premium.
Quins' response in the opening period came through a Nick Evans' three-pointer before the fly-half added two more after the interval.
Karl Dickson then went over late on, but Tom Palmer's touchdown gave Goode the chance to snatch the win. However, his effort hit the left-hand post.
In the same fixture last season, Wasps led 40-13 early in the second half only to succumb 42-40 after a superb comeback by the Stoop-based team.
That time, the High Wycombe outfit started with a high tempo and exposed a lacklustre Quins' side.
It seemed this match could go the same way when Launchbury touched down in the opening minute after early pressure.
Goode, a new signing from Worcester Warriors, was on target with the conversion as they took a 7-0 advantage.
However, that was quickly reduced by former New Zealand international Evans but, unlike the previous campaign, both teams were struggling to put phases together. And although Wasps' stand-off restored their seven-point lead after 13 minutes that was the last scoring action of the half.
Quins' prospects weren't helped by the unusually wayward kicking of their fly-half, who missed two opportunities before the interval. But he wasn't about to continue that streak as Conor O'Shea's men hit back after the break.
Evans was successful with two three-pointers to bring them to within one.
They were still finding it difficult to break down a stubborn Wasps' team, but the crucial score eventually came when Dickson finished from close-range after the forwards had done the hard yards.
Back came Wasps, though, and Palmer went over after a period of pressure but Goode couldn't quite kick the conversion.
For London Wasps:
Tries: Launchbury, Palmer
Yellow Card: Lawes
Pens: Evans 3
London Wasps: 15 Andrea Masi, 14 Christian Wade, 13 Ben Jacobs, 12 Charlie Hayter, 11 Tom Varndell, 10 Andy Goode, 9 Joe Simpson, 8 Ed Jackson, 7 Guy Thompson, 6 Sam Jones (capt), 5 Tom Palmer, 4 Joe Launchbury, 3 Jake Cooper-Woolley, 2 Tom Lindsay, 1 Matt Mullan.
Replacements: 16 Neil Cochrane, 17 Simon McIntyre, 18 Will Taylor, 19 James Cannon, 20 Ashley Johnson, 21 Charlie Davies, 22 Joe Carlisle, 23 Tommy Bell.
Harlequins: 15 Mike Brown, 14 Paul Sackey, 13 George Lowe, 12 Jordan Turner-Hall, 11 Ugo Monye, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (capt), 6 Luke Wallace, 5 George Robson, 4 George Merrick, 3 Will Collier, 2 Joe Gray, 1 Joe Marler.
Replacements: 16 Rob Buchanan, 17 Mark Lambert, 18 Paul Doran Jones, 19 Maurie Fa'asavalu, 20 Tom Guest, 21 Karl Dickson, 22 Ben Botica, 23 Charlie Walker.
Referee: Tim Wigglesworth