(CNN) -- Former world number one Lleyton Hewitt stepped up his comeback after injury by upsetting third seed James Blake in the opening round of the ATP tournament in Memphis.
Hewitt has been in fine form on the hard courts of Memphis.
Hewitt had hip surgery last August and has slipped outside the world top 100, but showed signs he is on the way back to his best with a 3-6 6-1 6-4 win over the American.
"It is tough to come back from surgery, not being seeded and getting all those tough first round matches," Hewitt told the official ATP Tour Web site.
"Last week I lost in a close match to (Mardy) Fish who went on to the final and this week I face Blake. We saw some good tennis out there today. I knew it was going to be tough for the loser of this match."
After sharing the opening two sets, Australia's Hewitt gained the crucial break in the seventh game, saving a break point on his own service in the next game.
Blake held for 5-4 and again put Hewitt under pressure in the next game, setting up three breaks points, all saved before Hewitt served it out with his seventh ace of the match.
He will now face compatriot Chris Guccione in the second round.
Top seed Andy Roddick also went through as he put out defending Memphis champion Steve Darcis of Belgium 7-6 6-2.
Roddick fired 20 aces and won 86 per cent of his service points to overwhelm Darcis, breaking twice in the second set to seal an easy victory. "I thought it was pretty solid," said Roddick.
Fish, beaten in the San Jose final by Radek Stepanek last week, continued his fine form, the seventh seed scoring a 6-1 7-5 win over Yen-Hsun Lu.
Meanwhile, Czech Stepanek, who beat Roddick on the way to the title last week, accounted for American Kevin Kim 6-4 6-2.
In the accompanying WTA tournament in Memphis, top seed Caroline Wozniacki of Denmark reached the quarterfinals with a 6-1 7-6 win over Severine Bremond of France.