Petrosian-Spassky, World Chess Championship, Moscow 1966, game 10
Petrosian and Spassky faced each other in two interesting and tight World Championship matches. In the first one in 1966, the reigning World Champion Petrosian defeated his opponent 12,5-11,5 to retain the title. The second match three years later was won by the challenger 12,5-10,5.
The presented 10th game from the first match is famous for its unique double exchange sacrifice at such a level. After nine games Petrosian was leading 5-4, and Spassky with the black pieces started aggressively by choosing to play the King's Indian Defence for the first time in the match. The challenger had active play on both wings and Black got reasonable chances after the opening, but Spassky underestimated Petrosian's ability to sense the danger long before it began. An over-optimistic bishop move by Spassky allowed the World Champion to implement his trademark exchange sacrifice. Just four moves later White sacrificed the second exchange and soon Petrosian's minor pieces completely dominated the position. White's graceful petit combination involving a queen sacrifice was a perfect way to finish this beautiful game.