Federer knocked out in shock loss to Baghdatis

The 24-year-old Cypriot, who had lost to the Swiss master in all six of their previous meetings, saved three match points before clinching the decisive tiebreak 7-4.

Baghdatis, beaten by Federer in four sets at the 2006 Australian Open final, kissed the ground in celebration after his opponent failed to return a powerful first serve. The shock win against the 16-times grand slam champion earned him a place in the fourth round against Spaniard Tommy Robredo, who beat Israel's Dudi Sela 6-3, 6-0.

"A lot of emotions are going through right now," the 27th-ranked Baghdatis said. "It's the best win of my career. I lost a lot of matches against those top guys, and it's a relief to win a match like that. It's a great moment for me."

Federer, beaten for only the second time in 13 matches this year and playing his first tournament since winning the Australian Open in January, reflected on the fine line between victory and defeat.

"I just couldn't find the way to win," the 28-year-old said. "I was maybe one shot away. That's how much it takes sometimes from winning or losing. That's why you can't say I played a bad match, and if I win I'm going to tell you it's a good match. It was a decent match, but maybe wrong choices at the wrong time for me."

American Andy Roddick booked his place in the fourth round with a clinical 6-3, 6-4 win over Dutchman Thiemo de Bakker, where he was joined by fourth seed Andy Murray, who suffered a late wobble before beating the American Michael Russell 6-3, 7-5.

Murray, beaten in last year's final by Spain's Rafa Nadal, appeared to be cruising to a routine victory when he led by a set and 5-2, but Russell offered dogged resistance to extend the Scot who was not at his best.

Russell played an inspired game to break Murray's serve and claw back to 5-5, but the 31-year-old American faltered at 5-6 and netted a backhand at matchpoint down.

"He hits it solid from the back of the court and stays close to the baseline," Murray said after his first ever meeting with Russell. "He's very quick, has a great attitude and made it difficult for me.

"I started well and was up in the second but he started to make me move whereas earlier I was dictating. The thing that was good about that match is a lot of long, tough games."

Big-serving Roddick broke his opponent once in each set and will next meet Austrian Jurgen Melzer, who gained a walkover when German Simon Greul withdrew due to illness.

In other matches, sixth-seeded Swede Robin Soderling eased past Spaniard Feliciano Lopez 7-6, 6-4 while ninth-seeded Frenchman Jo-Wilfried Tsonga came from a set down to beat Albert Montanes of Spain 4-6, 6-3, 6-3.

Meanwhile, women's second seed Caroline Wozniacki conceded she needed to improve after booking her place in the quarter-finals.

Wozniacki powered past Nadia Petrova in the third set of their fourth-round tie to reach the last eight but the Dane was called on to recover from a blip in the second as Petrova forced a decider.

Petrova won just two points on second serve as she fell apart in the third set, and Wozniacki showed her class to come through and win 6-3, 3-6, 6-0.

"It was a match where it just went up and down quite a bit, and you didn't really know what to expect," said Wozniacki. "It was not really a great rhythm there. I didn't feel the ball as well. But I'm just happy that I fought through and I won the match. That's the most important thing. I just think that I will be more ready for the next match."

That will be against Zheng Jie, a 6-3, 4-6, 7-6 (7/1) winner over Alicia Molik of Austria. Zheng needed two hours and 25 minutes to get past her unseeded opponent.

"Last time I played against Zheng I lost to her," Wozniacki added. "It was a tough match. She's a great player. She had a good start of the year, playing aggressively, taking the balls early. I need to be ready and focused."

There were routine straight-sets wins for the fourth and fifth seeds, Elena Dementieva and Agnieszka Radwanska, who will meet in the last eight.

Dementieva beat 19th seed Aravane Rezai 6-3, 6-3, while Poland's Radwanska beat another Frenchwoman, Marion Bartoli, 6-3, 6-2.

Sixth seed Jelena Jankovic of Serbia is through after she crushed the 17th-seeded Shahar Peer 6-2, 6-2, while eighth seed Samantha Stosur beat Vera Zvonareva 6-2, 7-5.

Maria Jose Martinez Sanchez, the 28th seed, defeated 13th-seeded Belgian Yanina Wickmayer 6-4, 6-4.