Top seed Rafael Nadal entered the second round of the Australian Open here Tuesday after his first round opponent Bernard Tomic retired after losing the first set 4-6.
Tomic left the court for a medical timeout after the first three games and decided to retire with an apparent left thigh injury after losing the first set.
"I feel really sorry for Bernard," said Nadal. "It is very tough to go out of a tournament like this when you are playing at home."
"I was in that situation a few years ago and I know how though is to take that decision," added the Spaniard.
Nadal staged a remarkable comeback in 2013 after staying away for nine months owing to a career threatening knee injury, winning two Grand Slams and finishing the year as World No.1.
Nadal will play Aussie wildcard Thanasi Kokkinakis in the second round Thursday.
