The Thai player, who was given a bye in thefirst round, celebrated becoming thefirst Asian ever toreachthe world's top ten on Monday, but he could not justify his high seeding against clay-court specialist Sanchez.
The Dane, seeking a first grand slam title and needing toreachthe last eight to have a chance of staying top of the rankings, beat Romanian 31st seed Monica Niculescu 6-2 6-2.
Kirilenko, seeded 14th, upset last year's Wimbledon champion Petra Kvitova 7-6 (7-3) 6-3 toreachthe last four of a top event for thefirst time in her career.