MELBOURNE, Australia (AP) — Men's top-seed Rafael Nadal has won his opening round match at the Australian Open. Also winning were No. 4 Andy Murray and fifth-seed Juan Martin del Potro.

Sixth-seed Roger Federer has opened his record 57th consecutive Grand Slam tournament with a 6-4, 6-4, 6-2 victory over wild-card entry James Duckworth in the first round of the Australian Open. The sixth-seeded Fedrerer needed just one hour and 46 minutes to complete his match amid temperatures in triple digits.

No. 13 seed John Isner was forced to retire in his opening-round match because of a foot injury. Isner was trailing 6-2, 7-6 against Martin Klizan when the match was stopped. He was the lone seeded American in the men's bracket.

Victoria Azarenka has moved into the second round, although the women's second seed had more difficulty than expected. Azarenka was forced into a first-set tiebreaker before earning a 7-6, 6-2 triumph over Johanna Larsson. Third-seed Maria Sharapova was also a winner as were 8th seed Jelena Jankovic, 10th seed Caroline Wozniacki and No. 11 Simona Halep.

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