Blake, seeded second behind American compatriot Andy Roddick, is defending the title he won here last year with a victory over Davis Cup teammate Roddick in the final.

Blake lost the title match last Sunday at Los Angeles to Czech Radek Stepanek, and is poised for a rise in form in the run-up to the US Open starting August 27.

The 27-year-old said he likes the state of his game as he advances on the hardcourts.

"It was a tentative start, we were feeling each other out," Blake said of his 149th-ranked opponent in a match played with Super Bowl- winning Indianapolis Colts coach Tony Dungy in the audience.

"I had to attack and not fall into playing his game. He's a guy who can beat you if you do that."

Blake fired eight aces, never faced a break point and broke the Brazilian three times as he won in 66 minutes.

"I opened my game up a bit at the end," said the winner. "After the first break of serve through, I felt the match was mine to take."

Blake moved into a showdown with American youngster Sam Querrey, who toppled towering Croatian Ivo Karlovic 5-7, 7-5, 7-6 (8/6) as two of the tallest men in tennis met in the second round.

Querrey, the world number 90, reached his third quarterfinal of the season after Memphis and Las Vegas back-to-back in February and March.

The Californian teenager saved match points at this level for the first time in his career as he won the ace-fest in two hours, 20 minutes.

The victory was a repeat of a first round win against the Croatian five months ago in Memphis.

Karlovic at 2.08 metres and Querrey, at 1.98, powered down tree-top serves with the American producing 14 aces and his opponent three more.

Two victories this week in the opening stages of the pre-US Open hardcourt season have wiped away bitter memories for Querrey of seven defeats in a row he suffered over recent months.

"It feels great to be in a quarterfinal again," he said.

Third seed Dmitry Tursunov threw away a hopeless second set to prepare for a definitive third, beating fellow Russian Teimuraz Gabashvili in a first-time meeting 6-3, 0-6, 6-2.

"Down 5-0 in the second, I really didn't have much of a chance in that set," said the winner. "I was just looking forward to getting into the third.

"My strategy was not to get broken early."

Tursunov reached the quarterfinals for the first time since two round of eight appearances on grass in June.

He next plays Kei Nishikori after the Japanese qualifier ousted German Michael Berrer 6-3, 3-6, 6-1.