Andy Murray recovered from a set down to beat Switzerland's Stanislas Wawrinka in the second round of the Open 13 in Marseille.
Murray fought back to win after losing the first set
Murray appeared to be in trouble after an opening set and a half which featured nine breaks of service.
But the British number one displayed huge resolve to force his way back in and claim a 3-6 7-6 (7-5) 6-1 win in just over two hours and 20 minutes.
Murray will now face Frenchman Nicolas Mahut, ranked 44th, in the last eight.
"I felt fine at first but then I started to struggle to keep the ball in court," said Murray.
"Everybody knows Stan can get nervous when a match gets tight. I know him well because he's one of my best friends on the tour."
As in Murray's first-round match against Jesse Huta Galung, serve proved difficult to hold and both players broke twice to take the score to 3-3 - Murray conceding the second with a double fault.
Wawrinka then consolidated and broke the 20-year-old Scot for a third time to leave the world number 32 serving for the set.
He had three set points before fourth seed Murray rallied to take the game to deuce, but Wawrinka finally claimed the set at the fourth opportunity.
Murray, nursing a niggling knee injury, continued to struggle at the start of the second and lost serve in the first game, but again he hit straight back.
There was a lot of pressure for me to come. That will teach me a lesson
Yet another Wawrinka break followed and this time the Lausanne-born player held to leave his British opponent deep in trouble.
After Murray finally held he levelled at 3-3 and, with the match settling down with no further breaks, a tie-break was required.
Murray took it 7-5 to take the match to a decider, and broke in the third, fifth and seventh games to progress in the tournament.
Australian Open champion Novak Djokovic, the top seed in France, lost 6-2 6-7 6-3 to unseeded Frenchman Gilles Simon.
The Serbian was playing his first match since withdrawing from his Davis Cup World Group clash against Russian Nikolay Davydenko on Sunday with flu.
Simon, the world number 30, broke in the seventh game of the first set which he took in 25 minutes and although Djokovic led 4-1 in the second set tie-break, he had to save a match point on his way to levelling the tie.
The Serbian struggled in the decider and at 4-1 down in the final set he was forced to call the trainer to the court.
"I was not 100% fit," said Djokovic. "I struggled in the long rallies and against a player as strong as Simon, that's not good enough.
"After the weekend in Moscow, the chances I would come here were not good but there was a lot of pressure for me to come. That will teach me a lesson."
Simon will now face compatriot Paul-Henri Mathieu, who put out another Frenchman, Michael Llodra 7-6 7-6 in the last eight.
Second seed Richard Gasquet was beaten 4-6 6-3 6-2 by Swede Robin Soderling.
The Frenchman started well, converting his only break opportunity in the first set, but then struggled with his serve and Soderling, who stopped the Frenchman in the quarter-finals here last year, took control.
Sixth seed Marcos Baghdatis sent down 15 aces as he saw off Ivo Karlovic, who produced 14 of his own but could not prevent a 6-4 6-4 defeat.