Roger Federer and Andy Roddick secured their places in round two of the Australian Open despite not finding their best form on day one.
Federer is trying to win his 10th Grand Slam title
Roddick came through a serious test of nerve against French wildcard Jo-Wilfried Tsonga in Melbourne.
The sixth seed, who beat Federer in an exhibition last week, eventually won 6-7 (18-20) 7-6 (7-2) 6-3 6-3.
Meanwhile, Federer was unusually inconsistent in seeing off Germany's Bjorn Phau 7-5 6-0 6-4.
The Swiss came back from a break down in the opening set before reeling off 11 straight games, but then let a lead slip in the third before finally finishing off Phau.
I think I got a little first-round jitters
"I got broken in the first set three times, and that makes you a little bit nervous," said Federer. "You try to stay cool, but I got a little bit nervous."
Federer now meets Sweden's Jonas Bjorkman, who fought back from a two-set deficit to beat Frenchman Olivier Patience 5-7 4-6 6-0 6-1 6-2.
Last year's runner-up, Marcos Baghdatis, won a punishing encounter against Rainer Schuettler, who was struggling with flu and had to call a medical time out in the third set.
The Cypriot, backed by a large contingent of his countrymen, came through 6-4 2-6 6-3 6-2.
"I didn't feel good today and it was not a good match but I am just happy to get through," said Baghdatis.
"I am playing really well in practice but today I wasn't really there on the court. I tried to stay cool and calm and obviously Rainer was injured."
In typical style, Marat Safin ensured the final match of day one stretched to almost three-and-a-half hours as he battled back to defeat Benjamin Becker.
The German rattled Safin with some impressive groundstrokes and big serves, and when he took a two sets to one lead, the Russian looked buried.
But a fired-up Safin levelled to set up an intense fifth set and clinched the decisive break at 3-2 before serving out the match.
Seventh seed Tommy Robredo enjoyed a more comfortable passage to the second round, beating fellow Spaniard Ruben Ramirez Hidalgo 6-4 6-4 6-0.
Serbian 14th seed Novak Djokovic stated his intentions with a quick fire 6-1 6-1 6-0 victory against Chile's Olympic champion Nicolas Massu.
Djokovic meets Spain's Feliciano Lopez, who beat American Brian Wilson 7-6 (10-8) 4-6 6-3 7-6 (7-3).
Richard Gasquet, seeded 18, had a straightforward 6-4 6-4 6-2 win over Filippo Volandri, and ninth seed Mario Ancic eased past Go Soeda 6-4 6-3 6-2.
Roddick was in trouble against Frenchman Tsonga after losing an epic first set tie-break 20-18 and slipping a break down in the second, but the American fought his way back.
606 DEBATE: Your thoughts on the action in Melbourne
Asked if he had been worried at any stage, Roddick said: "Absolutely, to say the least. I was wondering if we were ever going to finish the tie-breaker.
"I think I got a little first-round jitters. I played better as the match went on. I hope I can get better in the second round."
He will next play France's Marc Gicquel, a 3-6 6-7 (1-7) 6-4 6-1 6-0 winner over Australian Alun Jones.
Former US Open semi-finalist Joachim Johansson retired with blisters after just two games of his match against Guillermo Garcia-Lopez.
And Czech Jan Hajek lasted only one game more against Juan Carlos Ferrero as he doubled over on court suffering the effects of a stomach bug before withdrawing.
Thailand's Paradorn Srichaphan managed to complete his match but after losing 6-4 6-2 6-2 to Israeli qualifier Dudi Sela he announced he is taking time out to deal with a wrist injury.
"It's tendonitis. You can't just play with the heart, you've got to play with your body," said Srichaphan, who could be out for two months.
"I had no confidence in it today, but for the last three or four days I've just kept hitting less than an hour a day just to make sure that I can play the opening round here."