Roger Federer beat an injured Novak Djokovic 7-5 6-2 to set up an all-Swiss Monte Carlo Masters final with Stanislas Wawrinka after the Australian Open champion ousted David Ferrer 6-1 7-6 (3) on Saturday.
Holder Djokovic resisted for one set before pain in his right wrist was just too much to bear for the second-seeded Serb who bowed out on the first match point after one hour 14 minutes.
"It's unfortunate that when you're playing at this level against Roger, big tournament, that you are not able to play your game because something else is taking away all your energy," said Djokovic.
"This injury that has been present for last 10 days, and I tried not to think or talk about it, I did everything I could really, I was on the medications every day, I was doing different therapies, injections."
Djokovic could not specify the exact nature of the injury.
"I had the feeling he was not finishing off his shots with as much top spin as usual," Federer told Canal Plus.
"Even at 90 per cent, Novak is still strong and you still have to take your chances in the key moments and there were some in the first set where I had tough moments."
The much-awaited clash lived up to expectations early on, with 17-times grand slam champion Federer saving two set points on serve at 5-4.
Federer, who has never won the Monte Carlo Masters, broke in the following game and pocketed the set with an ace before Djokovic went to his chair holding his right wrist.
The second set was a stroll for the Swiss who produced a series of forehand winners as he moved 18-16 up in his head-to-head record against Djokovic.
Earlier, third seed Wawrinka showed no mercy against the giant-killing Ferrer.
The Swiss raced through the first set and kept his composure in the second when the Spaniard raised his level.
Sixth seed Ferrer, who knocked out eight-times French Open champion and world number one Rafael Nadal in the quarter-finals on Friday, was on the back foot throughout.
"It was the perfect start for me. I played very well in spite of the wind," Wawrinka told Canal Plus.
"He changed tactics in the second set, being more aggressive, and I became more hesitant but I played tougher then."
Wawrinka quickly opened a 5-0 lead after breaking twice with a passing shot and a forehand return winner.
The Swiss, looking to win his first Masters 1000 title, sealed the opening set with a stunning backhand winner down the line.
Ferrer saved a break point in the opening game of the second set but Wawrinka, whose 31 winners made up for 40 unforced errors, accelerated again in the tiebreak and prevailed on his second match point when his opponent netted a backhand.
Federer is 13-1 against Wawrinka but the world number three's only victory was on the Monte Carlo clay in 2009.
"It will be my first final against a Swiss player since Marseille in 2000 when I lost to Marc Rosset. At the time I was devastated, I thought I would never win a tournament," said Federer.
(Writing by Julien Pretot in Paris; Editing by Tony Jimenez/Rex Gowar)