American second seed James Blake suffered a shock defeat at the San Jose Open when he lost 6-7, 7-6, 6-4 to world number 103 Ivo Karlovic of Croatia in the second round on Thursday.

Top seed Andy Roddick and number four Marat Safin came through tight encounters to reach the quarter-finals, but Blake was upended by the tallest player on the ATP Tour.

World number six Blake served for the match at 5-3 in the second set and squandered four match points in the tiebreak before going down after two hours and six minutes.

Karlovic, who hammered 29 aces, smashed a forehand return for a winner on his third match point to set up a quarter-final against another American, fifth seed Mardy Fish.

"I had it on my racket," Blake told reporters. "I was up 5-3, 30-0. No one to blame but myself for that. I made some errors, missed a few serves and that was that. It was my fault."

After losing his serve in the eighth game of the second set, Karlovic, who missed half of 2006 through injury, broke back and saved four match points in the tiebreak before winning it 13-11.

That lifted his confidence and Blake began to feel the pressure in the decider, finally buckling in the 10th game when he double-faulted twice and though he saved two match points, he was powerless to stop the third as Karlovic crunched a winning return.

"When I lost my serve I knew I had only once chance to break so I was more aggressive and then I got more confident and my level went up," Karlovic said.

"He is one of the top players today so I am very happy."

RODDICK OUT-ACED

Roddick was out-aced 20-11 by wildcard Sam Querrey but one break in the first set and a solid tiebreak in the second took him to a 6-4 7-6 victory.

The 2004 and 2005 champion trailed 0-30 on his serve at 5-6 in the second set but held firm and now plays another American, eighth seed Vince Spadea.

Fourth seed Safin came through a tough test against world number 93 Yen-Hsun Lu of Taiwan before advancing 6-4 5-7 6-4 in just over two hours.

In the last eight, the Russian will play German Benjamin Becker, a 7-6, 1-6, 6-3 victor over compatriot Bjorn Phau.

"I feel a lot better than after my first match," Safin said. "I didn't really serve very well today but he got a bit tight at the end and I managed to get through so it's OK."

Fifth seed Fish recovered from a slow start to beat fellow American Sam Warburg 2-6, 6-4, 6-2.

The world number 25, a quarter-finalist at the Australian Open last month, said he was beginning to enjoy the fruits of his work in the off-season, when he reconstructed his forehand with his coach Todd Martin

"We hit a million forehands," Fish said. "Todd was even giving me the balls by hand at first. It was repetitive and annoying but it worked. Now I feel like my forehand is not a weakness anymore. It is still a work in progress but we are way ahead of where we thought we would be."

Spadea, at 32 the oldest player in the draw, edged out Spaniard Feliciano Lopez 4-6, 7-5, 7-6.

Seventh seed Lee Hyung-taik will take on defending champion Andy Murray after the South Korean recorded a 6-2, 7-6 win over German Simon Greul.