Wasps director of rugby Dai Young was left "gutted" after his team's stoppage-time defeat at Toulon.
Drew Mitchell's last-gasp try denied Wasps an historic victory as the European champions emerged 15-11 winners.
The former Wallaby crossed to salvage a dramatic win for the three-time Champions Cup winners and extend Toulon's 17-game unbeaten run at Stade Felix Mayol.
Guy Thompson looked to have given Wasps the triumph that would have clinched a quarter-final spot with a try 10 minutes from time.
But Jimmy Gopperth missed the conversion and Toulon managed a late score in the 81st minute to edge over the line.
The result saw Toulon take over at the top of Pool Five, and they can win the group with a bonus-point success at Bath next weekend when Wasps welcome Leinster to the Ricoh Arena.
Young said: "I'm really gutted for the players. I'm heartbroken for them. I couldn't have asked more of them. We didn't want to leave here with any ifs, buts or maybes and I thought they were excellent today.
"We were under pressure for large spells of that game but we got through it and with 80 minutes on the clock we looked like we had won the game.
"We pressurised them, we didn't give them space to play and we forced them into errors and made them doubt themselves for large parts of the game. It just would have been nice to come away with a really famous victory.
"We had a little bit of stage-fright in the first half. It was very similar to when we came out here two seasons ago.
"We gave them too much respect, became lateral and we didn't really take them on. But we talked about it at half-time. We wanted to really go at them and test them and we certainly did that and we grew into the game."
Bryan Habana's interception sparked a counter-attack that ended with Quade Cooper scoring the game's first try on 13 minutes.
Wasps were then reduced to 14 men when George Smith was shown a yellow card for a late tackle on Habana, and Eric Escande kicked Toulon 8-0 ahead.
Wasps managed to claim back three points through Gopperth before half-time while Frederic Michalak was off-target twice.
Gopperth converted a second penalty and a shock was on the cards when Thompson barged his way over on 70 minutes, only for Toulon to strike late on.