Roddick into San Jose last eight

Andy Roddick is in the quarter-finals of the SAP Open after beating Latvia's Ernests Gulbis 6-3, 7-6 (7/3).

Roddick rolled to a quick advantage in the opening set but the second offered a greater challenge as his Latvian rival stretched the match to 1 hour, 21 minutes at the $600,000 hardcourt event.

The top-seeded American managed only one break and had to fight off five break points to advance into the quarterfinals against Tommy Haas of Germany.

Roddick notched 10 aces, but was victimized by Gulbis on 11 serves.

Earlier, third-seeded James Blake beat Florent Serra of France, 6-4, 6-3 on Thursday to advance to the quarter-finals.

The American took one hour, seven minutes to gain a quarter-final date with sixth-seeded countryman Sam Querrey, who earlier took out Denis Gremelmayr of Germany, 6-3, 6-2 in 53 minutes.

Blake was dominant against the Frenchman, recording 13 aces, saving five break points and capitalising on two of three break opportunities. Blake won 85 percent of the points on his first serve.

Querrey finished Gremelmayr in swift fashion, posting all 12 aces in the match and broke his opponent three times while never losing his serve.

In other matches, fifth seed Mardy Fish of the United States advanced with a 6-2, 6-7 (5/7), 7-5 win over countryman Jon Isner in a battle of big servers.

Fish blasted 13 aces to 15 for Isner. Fish saved both break points against him and managed to capitalise on three such opportunities against Isner.

Qualifier Todd Widom took three sets to oust Taylor Dent, 6-7 (5/7), 6-3, 6-2 in two hours, one minute.