Stan Wawrinka beat good friend Roger Federer for only the third time in his career, reaching the semi-finals of the French Open on Tuesday with a 6-4, 6-3, 7-6 (7-4) defeat of the popular second seed.
There were some scattered jeers in the Lenglen court crowd as Wawrinka, the 2014 Australian Open winner, took victory to bring his record against his Swiss compatriot to 3-16.
Wawrinka, seeded eighth, attacked form the start in a strong wind, keeping Federer on the back foot to move into a first semi-final at Roland Garros after two hours, nine minutes with 43 winners and three breaks of serve.
"It is so tough to play Roger, who is a friend and someone I respect," said Wawrinka, who will face either Jo-Wilfried Tsonga or fifth seed Kei Nishikori.
"This was my best grand slam match on clay, it's an incredible moment for me.
"Everything clicked today, the wind made it tough, but I hit the ball very well. It was just an incredible match for me."
Wawrinka, who beat Rafael Nadal in Rome last month, had lost two Paris matches to Federer.
Earlier, Ana Ivanovic beat Elina Svitolina 6-3, 6-2 to reach her first semi-final at a grand slam since winning the French Open title in 2008.
The Serb will play for the Paris final against Lucie Safarova after the Czech 13th seed defeated Spain's Garbine Muguruza 7-6 (7-3), 6-3.
Serbian Ivanovic, seeded seventh, triumphed in windy Roland Garros conditions which made play that much more challenging on the clay.
Ivanovic advanced in 75 minutes over her Ukrainian opponent, breaking four of five times and striking 37 winners while making 30 unforced errors in the gusts.
"Obviously I'm very, very thrilled to be in the first semi-finals since 2008. It's been a long road and hard work," said Ivanovic. "Today was very, very tough match, even though the score doesn't indicate that.
"It was tough conditions and it was obviously for both of us - very, very gusty. I really tried to just execute my game plan and tried to move more, because in the windy conditions that's what you have to do.
"I was very happy I managed to do that so well and put pressure on her."
Ivanovic needed three match points to finally advance to her seventh win without a loss over the 21st-ranked Svitolina from Ukraine.
It was the same for Safarova: "It was very windy and the balls were really moving. You had to be ready. But I'm excited and ready for a semi-final."
