Drew Mitchell's stoppage-time try denied Wasps an historic win over European champions Toulon on Sunday afternoon.
The former Wallaby crossed to salvage a dramatic 15-11 win for the three-time Champions Cup winners, extending Toulon's 18-game unbeaten run at Stade Felix Mayol.
Guy Thompson looked to have given Wasps the victory that would have clinched a quarter-final spot with a try 10 minutes from time, b ut Jimmy Gopperth missed the conversion and Toulon mustered a final attack as time ran out.
The result saw Toulon take over at the top of Pool Five and they can win the group with a bonus-point win at Bath next weekend, when Wasps welcome Leinster at the Ricoh Arena.
Wasps stunned the holders with a remarkable 32-6 triumph in Coventry in November but were without key forwards Joe Launchbury, James Haskell and Nathan Hughes through injury.
Toulon recalled Steffon Armitage after he sat out the scrappy win over Bath last week, and the English flanker immediately lit up this tie.
His barnstorming break through black and gold jerseys brought Stade Felix Mayol to life and only the combined efforts of Joe Simpson and Charles Piutau denied Bryan Habana an early score.
Habana's interception sparked a counter-attack that ended with Quade Cooper scoring the game's first try on 13 minutes.
Ma'a Nonu released Josua Tuisova, who made plenty of yards before handing the scoring pass inside to Cooper. However, scrum-half Eric Escande was wide with his conversion.
Elliot Daly fared little better with a long-range penalty.
Wasps were then reduced to 14 men when George Smith was shown a yellow card by World Cup final referee Nigel Owens for a late tackle on Habana, and Escande kicked Toulon 8-0 ahead.
Wasps managed to claim back three points through Gopperth before half-time and their defence was to prove heroic at times in the second half.
Cooper missed with a drop goal from in front of the posts as Toulon were frustrated in attack.
Daly missed a second from distance, though replacement Frederic Michalak was also off key with the boot missing twice.
Meanwhile, Gopperth converted a second penalty to cut the lead to two points on 63 minutes.
But a shock looked on the cards when Daly used his pace to beat the cover defence and Thompson barged his way over for Wasps' only try on 70 minutes.
Gopperth pushed his conversion wide and Wasps' lead was 11-8.
They looked set to hold on amid more stubborn defending that appeared to frustrate Toulon.
But the holders showed their class late on as Mitchell raced onto Nonu's pass to score the match-winner in the first minute of added-on time.