Richard Haughton scored a late try as Wasps staged an astonishing fightback from 30-18 down at half time to earn their first win of the Aviva Premiership Rugby season.
Champions Leicester had looked on course for victory after the crossed for four first-half tries, with a double from Tom Varndell at least keeping the hosts in touching range. But the Tigers, who lost their opener against Northampton before struggling past newly-promoted Exeter last weekend, failed to score in the second half.
Wasps did not quite roar back into the game but four second-half penalties from Dave Walder did bring them level with 10 minutes to play before substitute Haughton's late converted try sealed a memorable win in front of their home fans.
Wasps were first on the scoreboard after Leicester's Jeremy Staunton missed an early penalty before launching an attacking cross-kick that Varndell intercepted in the air. The Wasps man spun clear of both Tom Croft and Scott Hamilton, and powered up the left wing to score with six minutes on the clock.
Walder's conversion attempt was way off target, although he did make amends three minutes later with a solid penalty kick to make it 8-0.
Leicester were denied a try in the 12th minute when the video referee ruled that Thomas Waldron's attempt at scoring via a post was too high. But they did get a penalty for offside which Staunton scored to get them on the scoreboard.
Walder punished a sloppy piece of by Alesana Tuilagi by booming over a penalty from halfway in the 15th minute, cheap points that irritated the Leicester management on the sidelines.
Leicester struck for real in the 19th minute following a sweeping move sparked when Wasps captain Tom Rees' missed a tackle. Three passes later, it was Tuilagi making some amends with the pass that put Matt Smith over on the left. Staunton's conversion failed.
Waldron then intercepted a loose pass from Nic Berry, but he lacked the pace to get over and Riki Flutey made the crucial tackle to leave rugby director Richard Cockerill pounding his desk with his fist in frustration.
Staunton hauled Leicester level with a penalty in front of the posts after 25 minutes, and Wasps were looking shaky under pressure. Sure enough, Leicester stormed ahead three minutes later – and it was a brilliant solo strike by Ben Youngs who broke away from a ruck, sidestepped some leaden-footed cover and accelerated clear to score between the posts. Staunton's conversion completed a fightback from 11-3 down that sent ripples of anxiety through the home support.
Just in time, Walder delivered a neat inside ball that Varndell juggled before securing and haring clear to score his 56th Aviva Premiership Rugby try on the left. Walder added a superb conversion from wide on the left, blowing the game wide open.
It was turn of Shaun Edwards to fume as the Wasps coach watched Mark van Gisbergen make a woeful hash of a tackle that allowed Billy Twelvetrees to score, and no sooner had Staunton converted than Leicester stormed back upfield and Croft slam-dunked a try over the line in the 37th minute, despite the attentions of two Wasps.
The Wasps team looked stunned to have shipped four tries and a bonus-point before the interval. But they made a storming fightback at the start of the second half, rewarded by two penalties from Walder in the 55th and 58th minutes.
But Leicester stood firm when defending their line, and broke out in the 64th minute to earn a chance of their first points of the second half. But Twelvetrees fired wide of the right-hand post. It was a costly miss because former England fly-half Walder was the form player and his third kick of the half in the 66th minute chopped Leicester's lead back to three.
And that was erased with 10 minute to go as Walder kept his nerve and fired home the levelling penalty. Adams Park then went wild in the 76th minute when Walder's clever kick foxed Geordan Murphy who allowed Haughton to pounce for an absolute gift which Walder converted.