Leicester Tigers inflicted the first defeat on champions Toulon in the European Champions Cup for more than a year with a 25-21 success at Welford Road on Sunday.
Leicester's Welsh fly half Owen Williams (C) makes a kick down-field during the European Champions Cup rugby union match between Leicester Tigers and Toulon at Welford Road stadium in Leicester on December 7, 2014
The twice former winners and five-time finalists had to dig deep to hold off the winners from the last two seasons despite being outscored two tries to one.
Their losing bonus point kept Toulon top of Pool 3 despite tasting defeat in the competition for the first time since a 19-15 reverse at Cardiff Blues in October last year.
Leicester are second a point behind with Ulster two points further back, whilst Scarlets are bottom.
World Cup winning New Zealander Brad Thorn crossed the whitewash for Leicester, for whom Welsh fly-half Owen Williams, surprisingly picked ahead of Freddie Burns, scored 20 points.
"It's a great win. It is the best we have probably played for 18 months," said Leicester's rugby director Richard Cockerill.
"It will be twice as hard to go there and win next week. Toulon will be really cheesed off, and it really doesn't get any more difficult than that."
Tries from another World Cup winner, Bryan Habana, and former Wallaby Drew Mitchell weren't enough to earn Toulon a victory.
After opening the scoring on 10 minutes with a penalty, Williams was gifted the chance to add a second when former Tiger Martin Castrogiovanni's excessive aggression at a ruck saw a penalty for Toulon overturned in Leicester's favour.
The hosts extended their lead on 19 minutes after Australian wing Mitchell fumbled following Mathew Tait's long kick forwards and Tom Youngs scooped up the ball before offloading to 39-year-old Thorn to barge over, with Williams adding the extras for a 13-0 lead.
Argentina fly-half Nicolas Sanchez landed two penalties to bring the champions back into contention but five minutes before the break Williams threw a loose pass that was picked off by South Africa flyer Habana, who ran the ball back 60 yards to score as Topulon went into the break level at 13-13.
Williams kicked Tigers back into the lead early in the second half after Toulon were penalised at a scrum.
But the champions won a Leicester scrum on the English team's 22 and scrum-half Sebastien Tillous-Borde darted down the blind side before putting in Mitchell to dot down.
But Williams landed three more penalties to just one from Sanchez as Leicester held on for victory.
"Everyone wants to win against us. We are the best. We have won everything, and it is normal for other teams to raise their game," said Castrogiovanni.
- Wasps roar back -
Earlier, two-time champions Wasps roared back into contention for a quarter-final place with a bonus point 32-17 win away at ailing French side Castres.
But Harlequins took control of Pool 2 with a 24-18 victory over three-time champions Leinster in London.
That put them clear on top with 12 points, three ahead of the Irish, who took a losing bonus point, while Wasps are another two points further back.
Wasps scored four tries to earn a bonus point, their third in three European games this season.
"This pool is very, very difficult. We've got a long way to go before we worry about qualifying," said head coach Dai Young.
Wasps got off to a dream start as fullback Rob Miller touched down in the fourth minute but Castres hit back almost immediately as hooker Mathieu Bonnello went over.
Ashley Johnson's quick hands set up Wasps' Kiwi No.8 Nathan Hughes for another try but centre Remi Lamerat's try made it 15-14 at the break.
Wasps scored a penalty try as Sitiveni Sivivatu was controversially yellow carded for denying Tom Varndell a score with a high tackle before Sailosi Tagicakibau rounded off the try-scoring against 14 men.
At the Twickenham Stoop, Quins scored the only two tries through No.8 Nick Easter and a 90-yard interception return from Asaeli Tikoirotuma.
Fly-half Ian Madigan scored all Leinster's points with the boot as the Irish side failed to turn second half possession and territorial domination into tries.
"We've not hit our straps but it's only half-time in Europe," said Quins coach and former Leinster player Conor O'Shea.
"It's a great start, we know what's coming next week (at Leinster). They're a great side so I'm really proud."
In Pool 4, record four-time champions Toulouse took over top spot from Glasgow by beating the Scottish side 19-11 in the south of France.