May 17 Czech Tomas Berdych tasted only his second victory in 15 clashes with Novak Djokovic to reach the semi-finals of the Rome Masters on Friday, coming from nowhere to stun the world number one 2-6 7-5 6-4 at the Foro Italico.
Djokovic looked poised for a routine victory with some majestic tennis putting him 6-2 5-2 ahead but Berdych's power game suddenly caught fire to leave the Serb reeling.
Apart from a victory in the 2010 Wimbledon semi-finals it has been a tale of woe for Berdych against Djokovic, including two defeats this year, but the world number six produced a display that augurs well for his French Open hopes.
For Djokovic his Roland Garros preparations have not gone to plan since beating Rafa Nadal to win the Monte Carlo title, losing early in Madrid last week and now snatching defeat from the jaws of victory against Berdych.
Frenchman Benoit Paire reached his first Masters Series semi-final with a 6-1 6-0 thrashing of Marcel Granollers.
Nadal takes on fellow Spaniard David Ferrer later with Roger Federer up against Poland's Jerzy Janowicz.
Serena Williams continued her march towards another title by pulversising Spaniard Carla Suarez Navarro 6-2 6-0 while her most fierce rival Maria Sharapova withdrew from her quarter-final with home favourite Sara Errani because of illness.
Former women's champion Jelena Jankovic was beaten by Romanian qualifier Simona Halep 4-6 6-0 7-5. (Reporting by Martyn Herman, editing by Justin Palmer)