Blake beat Serra in Indian Wells two weeks ago

Serra, ranked 64th in the world, avenged an Indian Wells loss to Blake in exactly two hours.

He will next face Spain's Feliciano Lopez, who defeated Russian 25th seed Marat Safin.

Rafael Nadal, Andy Roddick, Fernando Gonzalez and Novak Djokovic were among the seeds to progress.

Blake said: "I didn't play very well, it was another bad day. I'll try and put it behind me.

"I had a slow start and made a couple of bad tie-break points. I'm a little disappointed in the ways I played."

I don't want to go on the court knowing that I can't compete at my best Lleyton Hewitt

Second seed Nadal, fresh from his Indian Wells Masters victory, won his opener against Ricardo Mello of Brazil 7-6 (9-7) 6-2.

"The wind was changing all the time," said Nadal. "It was very, very difficult for me. But I arrive here with big confidence after playing very good tennis at Indian Wells."

Roddick, the third seed, hammered Argentina's Martin Vassallo Arguello 6-3 6-2, but there was disappointment for Safin, who lost 7-5 7-6 (7-2) to Lopez.

Earlier, Australia's former number one Lleyton Hewitt withdrew with a back injury.

Hewitt, who was set to face Raemon Sluiter, suffered the problem during his loss in Indian Wells to Serb Janko Tipsarevic less than a fortnight ago.

"I'm disappointed but my back has not come up as well as I'd have liked, which is frustrating," he said.

The 19th-ranked Hewitt, who won the Las Vegas title this month, said he had withdrawn to reduce the chance of further injury.