Melbourne, Australia: American John Isner has retired from his first-round match at the Australian Open with a foot injury after losing the first two sets to Slovakian Martin Klizan 6-2, 7-6 (6).
The 13th-seeded Isner was up 4-0 in the second-set tiebreak Tuesday before Klizan came back to capture the set.
Isner quit in the first game of the third set while trailing 30-0.
Isner injured his right ankle at the Hopman Cup exhibition event at the beginning of the year, but won a tournament in Auckland, New Zealand, last week.
Isner was the only American man seeded at the Australian Open.
