Florida: Juan Martin del Potro advanced to the second round of the Sony Ericsson Open on Wednesday, beating Ricardo Mello 6-4, 6-4.
Del Potro, the Argentine star who won the 2009 U.S. Open, was limited to three events last year because of a right wrist injury. He has jumped from 257th to 51st in the rankings 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."