Roger Federer's back and Kim Clijsters' passed their first first fitness test when the Australian Open started at Melbourne Park today, though Rafael Nadal was left worrying about a new injury.
Nadal had a scare when a tendon problem in his right knee nearly forced him to forfeit his match that he ultimately won easily.
Bothered by a left shoulder injury late last year, Nadal had his knee heavily taped today during a 6-4, 6-1, 6-1 win over Alex Kuznetsov.
The injury occurred in the most innocent of ways - sitting in a chair in his hotel room when he felt "a crack" in his knee and some "unbelievable pain."
He had an MRI scan late Sunday which showed no major damage to his knee, but before that, the incident left him thinking "I wasn't 100 per cent sure I would have a chance to play."
"That's in the past," Nadal said when asked about his shoulder injury in a post-match television interview. But it was a different story later when he talked about his knee.
"I was sitting on a chair in the hotel, I felt like a crack on the knee ... really strange, he said. "I stood up. I felt the knee a little bit strange. I moved the leg two times to try to find the feeling. After the second time, there was an unbelievable pain. I had no movement on the knee.
"I started with a little bit of a scare at the beginning, and nervous because I was really disappointed yesterday," he said. "But after the first 10 games ... I started to play with normal conditions.
"The best thing is I felt the knee very well. I really don't understand why it happened, but I am really happy that today I was ready to play and I played a fantastic match."
Federer withdrew from the Qatar Open after suffering back pain in the lead-up, but was at his clinical best, blasting winners from all angles as he wrapped up the match against qualifier Alexander Kudryavtsev in 98 minutes at Rod Laver Arena.
Clijsters, the defending women's champion, opened with a 7-5, 6-1 win over Portuguese qualifier Maria Joao Koehler, showing no signs of the hip spasms which forced her to withdraw from a tune-up event in Brisbane 10 day ago.
Li Na, who lost the Australian final to Clijsters last year, had a 6-3, 6-1 win over Ksenia Pervak of Kazakhstan. In the first featured match of the tournament, third-seeded Victoria Azarenka won 12 straight games to finish off Heather Watson 6-1, 6-0 in 67 minutes in the opening match on centre court.
Clijsters claimed later that the win was not as easy as it looked. "It was hard to really get a good rhythm out there," Clijsters said. "I did feel like I was seeing the ball probably not always as good as I would like to."
She said she had dealt with the "emotions and stress" of her hip injury, claiming she was lucky even to get a few warm-up matches in Brisbane.
Li was a trailblazer for China last year, reaching a Grand Slam singles final for the first time before losing to Clijsters at Melbourne Park. At the next major, she won the French Open to become the first player from China to win a Grand Slam singles title.
Most of the local attention though was on 19-year-old Bernard Tomic, who rallied from two sets down to beat No 22-seeded Fernando Verdasco 4-6, 6-7 (3), 6-4, 6-2, 7-5. A five-set win over the 2009 semi-finalist will no doubt give Tomic a confidence boost as he attempts to become the first Australian man since 1976 to win the national title.
"Today wasn't fun, it was torture," said Tomic, who reached the Wimbledon quarterfinals last year. "I don't know how I found the energy to lift, how I did it, but I thank the crowd."