A brilliant display by Andy Murray saw him beat Novak Djokovic for the first time to set up a semi-final clash with Rafael Nadal in the Toronto Masters.
The British number one had lost his four previous matches against the world number three, the defending champion, but his battling approach paid off.
Murray's tactics were spot on as he clinched a 6-3 7-6 (7-3) victory.
Nadal lost a marathon first set against Richard Gasquet in his quarter-final but went on to win 6-7 (12-14) 6-2 6-1.
The Spanish world number two has now won 27 successive matches.
He meets Murray less than a month after destroying him in straight sets on his way to taking the title at Wimbledon.
"It is a huge win for me, especially mentally - he has beaten me comfortably a few times in the last year or so"
It was a fascinating encounter between two different styles of play - with Murray's stubborn defence proving the match of the Serb's powerful groundstrokes.
Murray, the world number nine, broke Djokovic in his first service game and, after opening up a 3-0 lead, easily took the first set.
The second set was far tighter, with both players exchanging breaks, but Murray dominated the tie-break to move 6-1 ahead before serving out for victory.
"It is a huge win for me, especially mentally," Murray said. "He has beaten me comfortably a few times in the last year or so.
"So to win against him in straight sets, especially when he came back really well in the second set, was very pleasing."
606: DEBATE
Simon, ranked 22 in the world, beat 19-year-old Croat Marin Cilic 3-6 6-2 6-3 in an error-strewn encounter featuring 104 unforced errors, 64 by Cilic.
But the Frenchman is confident of progressing further against German Kiefer, who clinically disposed of seventh seed James Blake 6-1 6-2.
"I don't even know what's happening," said Simon. "I'm just so confident, I want to win every match, even if I'm tired. I know I'm playing very good at the moment."
~RS~q~RS~~RS~z~RS~35~RS~)