Amelie Mauresmo's grand slam jinx struck again on Tuesday when she was edged out 4-6 6-4 7-6 by Russian Elena Dementieva in the quarter-finals of the US Open.
The defeat also dented Mauresmo's hopes of climbing to the top of the rankings for the first time.
Second seed Mauresmo, still looking for her first grand slam title, twice led by a break in the second set but sixth seed Dementieva shrugged off 15 double faults and a stomach upset to reach the semi-finals for the second time.
In a match containing 14 breaks of serve, Dementieva showed huge mental strength and despite squandering a 2-0 lead in the third set, she held her nerve to win the final-set tiebreak 7-1 and take her place in the last four.
The Russian now plays either twice former champion Serena Williams or Jennifer Capriati in the semi-finals.
Mauresmo can still become world number one but American Lindsay Davenport could overtake her if she wins the tournament.