Rafael Nadal survived a major scare against David Nalbandian to booking his place in the quarter-finals of the BNP Paribas Open.

But the Spaniard showed plenty of resolve to break back to take it to a tie-break which he won.

Nalbandian provided little resistance in the decider as Nadal strolled through it to clinch a 3-6 7-6 (7-5) 6-0 victory and a last eight meeting with Juan Martin Del Potro.

Roger Federer was also made to sweat by Fernando Gonzalez before booking his place in the quarters.

The 13-time grand slam champion dropped the second set - the first he has lost in the tournament - but still triumphed 6-3 5-7 6-2.

Federer's first serve percentage slipped to just 47% in the second set against the 17th seed from Chile, but he bounced back in the decider to win in one hour 49 minutes.

The Swiss second seed will take on Fernando Verdasco in the next round after the 10th-seeded Spaniard survived a second-set scare to claim a 6-4 3-6 6-1 win over Philipp Kohlschreiber.

Andy Murray earlier progressed against 15th-seeded Spaniard Tommy Robredo, who was forced to retire with a wrist injury.

The Scot, seeded four, took the first set 6-2 and was 3-0 up in the second when Robredo threw in the towel.

Next up for Murray is veteran Croatian Ivan Ljubicic, who beat 22nd seed Igor Andreev 4-6 7-6 (7/5) 7-6 (7/4).

On a day of few shocks, there were also wins for sixth seed Del Potro, third seed Novak Djokovic and seventh seed Andy Roddick.

Del Potro beat American wild card John Isner 7-6 (7/4) 7-6 (7/3) in a match which featured no breaks of serve, defending champion Djokovic also required two tie-breaks to beat Stanislas Wawrinka 7-6 (9/7) 7-6 (8/6) and Roddick edged out 12th-seeded David Ferrer 7-6 (7/5) 3-6 6-3.

Dinara Safina's hopes of reaching the world number one spot were put on hold after the Russian lost in three sets to Victoria Azarenka of Belarus in the quarter-finals of the women's event.

Safina would have overtaken Serena Williams at the top of the rankings if she had reached the final but produced a below-par display against the eighth seed.

"If I play like this, it will definitely not come," she said.

Azarenka will now meet fourth seed Vera Zvonareva after the Russian beat Caroline Wozniacki 6-4 6-2.