KEY BISCAYNE, Fla. (AP) 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, will face Philipp Kohlschreiber.
Kevin Anderson also advanced, beating Nikolay Davydenko 6-4, 6-3.
In women's first-round play, Bethany Mattek-Sands celebrated her 26th birthday with a 6-1, 6-4 victory over Sofia Arvidsson. Mattek-Sands will face top-ranked Caroline Wozniacki on Thursday.
Kimiko Date-Krumm, at 40 the oldest player in the women's singles draw, beat Zuzana Ondraskova 6-4, 6-3.