The giant midfielder shone in both defence and attack to help his team reach the final four for the second time in three seasons.
Toulon hooker Sebastien Bruno has already claimed that the 2010 Amlin Challenge Cup finalists play their best rugby in continental competition and Bastareaud believes that may well be because of the pleasure they get from the unique nature of the tournament.
"Personally, I love these big European games," said Bastareaud.
"I love games with a lot of pressure and with a huge team as your opponents.
"I don't want to be satisfied with just a good game myself, either: I want to be excellent every weekend.
"Friday was a big test for us with a lot of pressure and we passed it. Harlequins are a big name in European rugby and they're the English Premiership leaders.
"We were very satisfied with that win because we did exactly what we had planned during training in the week leading up to the match.
"We had a lot of ball and we faced up to the physical challenge really well. When you play English teams it's always the same: it's very tough and very physical, so we were prepared for it. We won that physical challenge and, when you do that, it becomes a lot easier to go on and win the game."
Toulon now take on Stade Francais at the Stade Felix Mayol on Friday, April 27, with the winner set to face either Biarritz Olympique or Brive in the tournament's showpiece.