World number one Roger Federer [Images] posted his third win of the season over Tommy Haas with a 6-1, 6-3 victory into the fourth round of the Nasdaq-100 Open on Monday.

The Swiss top seed unleashed his majestic game at the expense of the German, who also lost to Federer at Doha and the Australian Open.

Federer, with childhood hero Boris Becker watching from the stands, needed just 68 minutes to book his place in the next round.

"I played a really solid match," he told reporters after defeating Haas for the sixth time in eight meetings.

"I started well, hit the ball well and didn't miss much. It was tough for Tommy, I didn't give him any easy balls."

Federer is aiming for his 10th ATP Masters Series shield and his second consecutive title after beating James Blake for the Pacific Life Open trophy this month.

Briton Tim Henman was stunned by unheralded German qualifier Simon Greul 0-6, 6-1, 7-5 while 2004 winner Andy Roddick [Images], seeded fourth, defeated Spain's Fernando Verdasco 6-3, 6-4.

Henman looked in command after sweeping the opening set in 18 minutes as the 24-year-old Greul, a first-round winner over Paradorn Srichaphan [Images], won just four points.

The momentum shifted in the second set when the 130th-ranked Greul, who missed four months in 2003 with an ankle injury, asserted his game.

SHOCKED HENMAN

Playing in his first Masters Series tournament, the German baffled Henman as he levelled at a set apiece, then recovered from a break down in the third to complete the upset.

"I'm shocked," Henman, who had notched up back-to-back wins over former world number ones Marat Safin [Images] and Lleyton Hewitt [Images] in the previous rounds, told reporters.

"To play as I did and for him to play that badly... I didn't take anything for granted. I wanted to keep the pressure on.

"I missed one forehand (in the third game of second set). I was then playing a different player.

"After having beaten Safin and Hewitt and then having a match like this. It certainly doesn't sit well with me."

Blake defeated Finn Jarkko Nieminen 6-3, 4-6, 6-1 to continue a purple patch which guided him to the Pacific Life Open final earlier this month.

Women's fourth seed Maria Sharapova [Images] survived a scare before she booked her place in the quarter-finals. She needed five match points before overcoming fellow Russian Maria Kirilenko 3-6, 6-4, 6-1.

Former Wimbledon champion Sharapova avenged her defeat by Kirilenko in Beijing [Images] last September despite producing 43 unforced errors.

"I was down a set but I tried to hang in," Sharapova told reporters following the battle that lasted over two hours.

"I wasn't playing my best, that's for sure.

Russian Svetlana Kuznetsova earned a walkover into the quarter-finals after seventh seed Patty Schnyder withdrew with an ankle problem.

There were also victories for France's [Images] Tatiana Golovin [Images], who put out sixth seed Elena Dementieva 6-2, 6-1 and former Roland Garros winner Anastasia Myskina [Images], a 6-3, 6-2 winner over Russian compatriot Anna Chakvetadze [Images] 6-3, 6-2.

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