Petrosianic: <Damn, terrible loss for Petrosian. Only this loss stood between Petrosian and an unbeaten Olympiad record in a 130-game(!), 10 Olympiad career.>Yeah, it was, but he got revenge in this game:
Huebner vs Petrosian, 1976
Critics said of Petrosian that he'd rather defend against a Mate in 5 than play his own Mate in 4, but that's pretty much what Huebner does here.
White can win this game easily with 37. Qe8+ Kg7 38. Re7+ Kh6 39. Qf8+ Kh5 40. Rxh7++. The only way to prevent it is to give up Queen for Rook on Move 38.
Instead, Huebner plays 37. g3?, defending against Petrosian's threat. Petrosian plays 37... Nxf4. The next move Huebner sees what he missed before, but it's not there any more. 38. Qe8+ Kg7 39. Re7+ Kh6, and now Qf8+ doesn't work, because White no longer has an f pawn.
What time pressure gave Huebner in this game, it took away in the 1976 game. And the prize was a spot in the 1977 Candidates.