Worcester stunned Leicester with a 79th-minute Ted Hill try to record their first Gallagher Premiership victory of the season, 44-37 at Welford Road.
Warriors had led 37-11 midway through the second half after running in five tries, before Tigers mounted a late comeback which saw them level the game with four minutes remaining after George Ford's converted try.
However, replacement Hill did just enough to score in the corner at the end to shock the hosts and get the Warriors' campaign up and running.
Worcester made the perfect start at Welford Road, storming into a 14-0 lead inside six minutes.
Duncan Weir scored all 14 points, slamming down the opening try after two minutes following Bryce Heem's charging run with the try-scorer also converting, then doubling the visitors' advantage as he touched down by the posts after Pierce Phillips and Sam Lewis' tidy set-up.
Tigers soon settled with Ford kicking a penalty in front of the posts and he repeated the feat minutes later.
Weir scored three points of his own after Dan Cole's deliberate knock-on, before Worcester ran in their third try. Heem was the catalyst once more with hooker Jack Singleton eventually going over in the corner.
It took the hosts 25 minutes to score their first try. Ford found touch with a penalty, with the pack driving Guy Thompson over in the corner.
Ford missed the extras and Worcester were proving clinical at the other end, bagging the bonus-point through Chris Pennell. Weir missed the conversion but made amends with a penalty on the cusp of half-time to ensure Geordan Murphy's men had plenty to ponder at the break.
Leicester looked quicker and slicker immediately after half-time, but went without reward.
Worcester piled more misery on the hosts when Hill battled over for a debut try and Worcester's fifth to match the efforts of their 31-27 win at Welford Road last season.
Tigers were handed a lifeline when Jonny May galloped away to the corner for his fifth try of the season and it got better five minutes later when David Denton wrestled through.
Ford drilled the extras this time, but Leicester were still in need of two converted scores of levelling.
Number eight Sione Kalamafoni put the hosts within seven points after his try and Ford's impressive conversion from out wide.
After one failed attempt, Leicester levelled the game when Ford skipped away from midfield, thwarting tackles before crossing the whitewash.
He converted – but it was not enough as Hill crossed in the corner and Weir kicked the conversion with the final play.