Long-time rivals Roger Federer and Rafael Nadal sought to play down a rare public spat between them as both enjoyed crushing Round One wins at the Australian Open yesterday.

Nadal and Federer after their first round wins in Melbourne yesterday

Federer said he was "completely cool" despite Nadal accusing him of not pushing hard enough for better players' rights, while the Spaniard regretted his comments made to media earlier.

"Things are fine between us, you know. I have no hard feelings towards him," Federer said.

"He's mentioned many times how he gets a bit tired and frustrated through the whole process, and I shared that with him. It's normal. But for me, obviously nothing changes in terms of our relationship. I'm completely cool and relaxed about it."

The short-lived row threatened to overshadow Day One action at the year's first Grand Slam, where women's champion Kim Clijsters went through in straight sets alongside last year's runner-up, Li Na of China as temperatures soared to 34 degrees Celsius (93 degrees Fahrenheit).

Nadal said he should not have taken Federer to task publicly. He had complained that the ATP Player Council president was not speaking out on issues such as more prize money and an easier schedule. "These things can stay, must stay in the locker room. I have a fantastic relationship with Roger. That's what it should be," said Nadal.