Answer: SPASSKY

AnswerCrossword Clue
SPASSKY1972 Fischer foe
SPASSKY1972 Fischer opponent
SPASSKYWinner over Petrosian in 1969
SPASSKY1969-'72 World Chess Champion
SPASSKYFormer world chess champion Boris
SPASSKYFormer chess champion Boris
SPASSKYRussian chessmaster
SPASSKY1972 Match of the Century participant
SPASSKY1972 "Match of the Century" loser
SPASSKYFischer beat him in Reykjavik
SPASSKYBig name in chess
SPASSKYChess champ Boris
SPASSKYLoser to Fischer in Reykjavik