Juan Martin del Potro won yet another match in his return from a right wrist injury, beating Ricardo Mello 6-4, 6-4 on Wednesday in the first round of the Sony Ericsson Open.
Del Potro, the Argentine star who won the 2009 U.S. Open, was limited to three events last year because of the injury. He has jumped from 257th to 51st in the world this year, winning the Delray Beach International last month and reaching the semifinals in San Jose, Memphis and Indian Wells.
"I'm still improving match by match," said del Potro, 18-5 this year. "It's a good signal for my future, for my comeback, and for recovering my game."
He'll face Philipp Kohlschreiber in the second round.
"I feel tired, but I'm really glad with my success between San Jose and today, and I have more energy to stay alive in this tournament," del Potro said. "I really like playing here in Miami. Many South American people come to see the tournament, so we feel really well."
In a night match, James Blake rallied to edge Michael Russell 3-6, 7-6 (7), 7-6 (3).
Blake spent most of last year nursing shoulder and right knee injuries, and ended the season ranked out of the top 100 for the first time since 2001. Ranked 177th, he got into the main draw as a wild card.
"It's important just because people can see the desire is still there," Blake said. "It's still going to take some time for me to get my form back. Tonight was very encouraging because I wasn't playing my absolute best tennis but I still got a win."
Kevin Anderson also advanced, beating Nikolay Davydenko 6-4, 6-3.
In women's first-round play, former world No. 1 Dinara Safina beat Jelena Dokic 6-4, 6-4.
Safina missed three months last year because of a back injury.
"Slowly, I am starting to get some matches behind me," Safina said. "I'm still far from being at my best, but we are working day by day and with each win it helps me to get closer to where I want to be."
Bethanie Mattek-Sands celebrated her 26th birthday with a 6-1, 6-4 victory over Sofia Arvidsson, setting up a match against top-ranked Caroline Wozniacki.
Mattek Sands lost the one time she played Wozniacki, in the 2009 Italian Open.
"It's a good challenge for me and I like challenges," Mattek-Sands said. "You just got to go into the match knowing you're not going to get free points. For me, I'll stick to my same game plan. I'm going to play aggressive."
Kimiko Date-Krumm, at 40 the oldest player in the women's singles draw, beat Zuzana Ondraskova 6-4, 6-3.