(REUTERS) - Roger Federer and Novak Djokovic cruised into the quarter-finals of the BNP Paribas Open at Indian Wells on Wednesday, after Wimbledon champion Andy Murray and Australian Open winner Stanislas Wawrinka both fell in the fourth round.
In a tournament full of surprises, Federer and Djokovic struck a blow for the old world order with the Swiss beating Germany's Tommy Haas 6-4, 6-4 and the Serb coming back to down Croatia's Marin Cilic 1-6, 6-2, 6-3.
Federer and Djokivic are the only players ranked in the world's top 10 to reach the quarter-finals, after 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 (7-1), 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.
Already a four-time champion at Indian Wells, Federer is now on a nine-match winning streak after taking the title in Dubai before heading to Indian Wells. But he said he was wary about Anderson, who has reached a career-high ranking of 18 after making the final of his last two tournaments.
"I know how tough he is," Federer said. "He's the best here usually in the States, outdoors on the hard courts. That's when he's had his biggest success.
"I'm aware that this is not going to be an easy match just because he's not ranked in the top 10."
Djokovic had won each of his previous seven encounters with Cilic but his perfect record was in danger after he lost the opening set to the towering Croatian, winning just three points on return.
But the Serb quickly got his act together, and broke Cilic twice in the second set then once in the deciding third to safely advance to the last eight.
John Isner kept American hopes alive with a 7-6 (7-3), 3-6, 6-3 win over Spain's Fernando Verdasco, while Latvia's Ernests Gulbis defeated Roberto Bautista of Spain 7-6 (7-0), 4-6, 6-2.
A third Spaniard, Feliciano Lopez, was sent packing by unseeded Frenchman Julien Benneteau, losing 6-3, 7-6 (7-4).
In the women's draw, second seed Agnieszka Radwanska booked her spot in the semi-finals after a two-and-a-half hour slugfest with Serbia's Jelena Jankovic.
Radwanska looked to have regained control when she led 4-0 in the third set but only sealed the win by reeling off the last two games when Jankovic drew level at 4-4.
Jankovic actually won two more points than Radwanksa overall but still finished behind in their floodlit thriller.
Radwanska's semi-final opponent on Friday is Romania's Simona Halep, after she cruised into the next round with a 6-2, 6-2 victory over Australian qualifier Casey Dellacqua.
Halep only needed an hour to wrap up a lopsided victory and is poised to become the first Romanian woman to break into the top five when the updated world rankings are released on Monday.
The only other Romanian women to make the top 10 were Virginia Ruzici, who won the French Open in 1978 and made it up to No.8 in the world, and Irina Spirlea, who climbed as high as seven.
"It means a lot," Halep said. "I'm now the best Romanian in history for rankings - but my goal is to win a Grand Slam, and then maybe I'll be the best, because Virginia won the French Open."