Roger Federer cruised into the quarter-finals of the PNB Paribas Open at Indian Wells on Wednesday (local time) after Wimbledon champion Andy Murray and Australian Open winner Stanislas Wawrinka both fell in the fourth round.
In a tournament full of surprises, Federer struck a blow for the old world order with a 6-4 6-4 win over German Tommy Haas.
The only player left in the men's draw with a higher ranking than world number eight Federer is Serbia's Novak Djokovic, who was due to play Marin Cilic in Wednesday's feature night match.
Wawrinka and Murray joined the big-name casualties when they both crashed to lower-ranked opponents on another day of upsets in the Californian desert.
Wawrinka suffered his first loss this year when his 13-match winning streak came to a shuddering halt as he was beaten 7-6(1) 4-6 6-1 by South African Kevin Anderson.
"It wasn't really on my mind that he had won Australia," said Anderson, whose next opponent is Federer.
"It feels great to beat somebody who obviously has just won a grand slam."
Murray was blown away by Canada's Milos Raonic, one of the biggest servers in men's tennis.
Despite winning the first set, the Scotsman was unable to contain the raw power of Raonic, who triumphed 4-6 7-5 6-3 in a little over two hours.
Raonic blasted 15 aces past his bewildered opponent, who is one of the best returners in the game, and won a staggering 83 per cent of points when he landed his first serve.
Murray did break Raonic's serve in the opening set and again in the deciding third to lead 2-1 but lost the next four games in a row against the 6ft 5in (1.96 metre) tall Canadian.
"To get broken two consecutive times in that situation isn't good enough. I played poor tennis at that stage. I didn't make enough balls and I missed some really easy shots," Murray told reporters.
"It's tough to win matches like that, because against him, he obviously wins a lot of free points with his serve. So over the course of the set, if you give up enough unforced errors on basic shots, then with the amount of free points he gets on his serve, that's going to add up to a negative result."
Raonic's next opponent in the quarter-finals will be Ukrainian giant killer Alexandr Dolgopolov who followed up his upset victory over Rafa Nadal on Monday with a comprehensive 6-2 6-4 drubbing of Italy's Fabio Fognini.
"I think the most important thing is obviously my serve and the beauty of that is nobody can affect me," Raonic said.
John Isner kept American hopes alive with a 7-6(3) 3-6 6-3 win over Spain's Fernando Verdasco while Latvia's Ernests Gulbis defeated Roberto Bautista of Spain 7-6(0) 4-6 6-2.
A third Spaniard, Feliciano Lopez, was sent packing by Frenchman Julien Benneteau, losing 6-3 7-6(4).
In the only match completed in the women's draw, Romania's Simona Halep cruised into the semi-finals with a 6-2 6-2 victory over Australian qualifier Casey Dellacqua.
Halep only needed an hour to wrap up a lopsided victory and will now play either second seed Agnieszka Radwanska or Jelena Jankovic on Friday (local time).
"I had no pressure," said Halep, who is poised to break into the world's top five rankings for the first time.
"I was more relaxed than yesterday. I said that if I'm in the quarter-finals I have to enjoy it."