London Wasps are looking like late contenders for the Guinness Premiership, after they began their usual late season charge with a 23-16 win away at a sold out Stoop against Harlequins on Saturday.
Lawrence Dallaglio's team trailed 13-0 just before half-time but Quins had no answer once the Wasps forwards stepped up a gear.
Number eight James Haskell and academy wing Chris Bishay scored tries, while full-back Mark Van Gisbergen's accurate kicking - he slotted three penalties and two conversions - left Quins floundering.
Quins made all the early running and were good value for a comfortable advantage given to them by wing Simon Keogh's try and eight points from fly-half Adrian Jarvis.
But they could not sustain the momentum and Wasps, with England Six Nations training squad member Haskell a dominant force, moved into third place above Gloucester, who tackle leaders Leicester at Kingsholm tomorrow.
It was Wasps' first Premiership away win of the campaign and owed everything to the unrelenting effort of their forwards after Quins had threatened to run away with it.
Wasps, minus 13 players due to injuries or international call-ups, should have gone ahead after two minutes, but Van Gisbergen hit the post with a 20-metre penalty attempt.
And that was the closest they came until Van Gisbergen found his range with the final kick of a one-sided opening half.
Quins, with scrum-half Andy Gomarsall calling the shots in expert fashion, dominated territory and possession to such an extent that Wasps were pinned deep inside their own half and could find no way out.
Quins full-back Mike Brown launched a brilliant solo run that only ended two metres short of the visiting line when Bishay completed a superb tackle, but the home side were not to be denied eight minutes later.
England centre Stuart Abbott, making his first appearance since recovering from a bout of concussion, split open Wasps' midfield defence with an exquisite inside pass that Keogh collected and finished off in blistering fashion.
Jarvis slotted the touchline conversion and then added a penalty, and Wasps were just grateful to stay in touch through Van Gisbergen penalties either side of half-time.
Quins though should have been further ahead, and when Van Gisbergen completed his penalty hat-trick just after Ayoola Erinle appeared off the Wasps bench for his first outing since suffering a broken leg more than three months ago, alarms bells started ringing.
Quins' problems were compounded as Gomarsall limped off, and the game's increasingly feisty nature was underlined when Erinle punched home skipper Paul Volley, earning him a yellow card.
But Wasps had momentum, and they went ahead for the first time through lock Dan Leo's surging run that set up Haskell for a high-class try.
Abbott was then sin-binned for an offence during the build-up, and Wasps saw scrum-half Mark McMillan stretchered off after Van Gisbergen's conversion made it 16-13.
The game continued to simmer but Wasps had control up front, and without Gomarsall's calming influence Quins found themselves drifting.
Wasps struck again 15 minutes from time, with the impressive Haskell acting as link-man before the visitors spun possession wide and Bishay galloped over after collecting Van Gisbergen's pass.
Van Gisbergen added the extras, leaving Quins 10 points adrift and in dire need of inspiration as Wasps maintained their stranglehold.
Jarvis kicked a late penalty, yet Wasps finished the second period well on top and comfortably closed the game out, although Quins secured a losing bonus point.
Pens: Jarvis 3
Tries: Haskell, Bishay
Cons: Van Gisbergen 2
Pens: Van Gisbergen 3
Harlequins: 15 Mike Brown 14 Simon Keogh 13 Mel Deane 12 Stuart Abbott 11 Tom Williams 10 Adrian Jarvis 9 Andy Gomarsall 8 Chris Hala'Ufia7 Paul Volley (c) 6 Andre Vos 5 Jim Evans 4 Ollie Kohn 3 Ricky Nebbett 2 Tani Fuga 1 Ceri Jones
Replacements: 16 James Hayter, 17 Mark Lambert, 18 Nicolas Spanghero, 19 Tom Guest, 20 Steve So'oialo, 21 Tosh Masson, 22 Charlie Amesbury
Wasps: 15 Mark Van Gisbergen, 14 Chris Bishay, 13 Fraser Waters, 12 James Brooks, 11 Tom Voyce, 10 Alex King, 9 Mark McMillan, 8 James Haskell, 7 Jonny O'Connor, 6 Lawrence Dallaglio (c), 5 George Skivington, 4 Dan Leo, 3 Nick Adams, 2 Joe Ward, 1 Alistair McKenzie
Replacements: 16 Rob Webber, 17 Peter Bracken, 18 Simon Shaw, 19 John Hart, 20 Simon Amor, 21 Jeremy Staunton, 22 Ayoola Erinle
Referee: Martin Fox
Touch judges: Peter Huckle, Andy Watson
Assessor: Paul Bridgman
Television match official: Clive Leeke