Here's Geller's blown endgame v Fischer from the 1970 IZ, Geller was leading the tourney at the time and would qualify for Candidates:
http://www.chessgames.com/perl/chessgame?gid=1044663
By move 25, there were 3 v 4 pawns and only rooks on the board, Geller had offered a draw and Fischer turned him down. Soviet GMs at the tourney were quoted as saying, 'Why does Fischer not accept draws in such positions? Drawing for Russian players here is simply a matter of technique.'
At 65 there are just 2 rooks and 3 pawns left.
Geller then blunders on 67 and resigns a few moves later.