Roger Federer and Novak Djokovic cruised into the quarter-finals of the BNP Paribas Open at Indian Wells 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 Federer beating Germany's Tommy Haas 6-4, 6-4 and Djokovic 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, 4-6, 6-1 by South African Kevin Anderson.
Murray was blown away by Canada's Milos Raonic 4-6 7-5 6-3.
Isner flies the flag
Elsewhere, John Isner kept American hopes alive with a 7-6, 3-6, 6-3 win over Spain's Fernando Verdasco, while Latvia's Ernests Gulbis defeated Roberto Bautista of Spain 7-6, 4-6, 6-2.
A third Spaniard, Feliciano Lopez, was sent packing by unseeded Frenchman Julien Benneteau, losing 6-3, 7-6.
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'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.