Venue: Melbourne Park Date: 18-31 January
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Del Potro won his first Grand Slam at the US Open in September
Fourth seed Juan Martin del Potro progressed to the third round of the Australian Open after a marathon five-set victory over American James Blake.
The US Open champion broke Blake in the 17th game of the fifth set before holding serve to win 6-4 6-7 (3-7) 5-7 6-3 10-8 in a little over four hours.
Earlier, defending champion Rafael Nadal crushed Slovakian Lukas Lacko 6-2 6-2 6-2 on Rod Laver Arena.
And seventh seed Andy Roddick beat Brazil's Thomaz Bellucci 6-3 6-4 6-4.
Del Potro, 21, had been in danger of becoming the highest-ranked men's player to be eliminated before he rallied from a break down in the fifth set.
The 30-year-old Blake, who twice had treatment on his right knee and needed it strapped during the match, had held a 2-0 advantage, but Del Potro managed to fight back to put the match back on serve.
Del Potro had the opportunity to serve for victory in the 12th game only to be denied by Blake, before he finally took the advantage again at 8-8 and sealed it with a big serve that Blake was unable to return in the next game.
Del Potro said he was still experiencing discomfort from a wrist injury that forced him out of last week's Kooyong Classic warm-up tournament, but that he was confident he would be fit for his third-round match against German Florian Mayer.
"Yes, I have a little bit of pain, but I can play," he said. "I think I have many good things right for the next match.
Nadal wasted little time in winning his second-round match
"Blake was fast. He played very strong with his forehand. He never missed easy points, easy forehands.
"It's very difficult to keep trying, keep going. You have to be focused every point, every time, and try to take your chance. I had my chance in the last set."
By contrast, it was plain sailing for world number two Nadal, who converted five of his six break points against the 22-year-old Lacko.
"I played a serious match. I think I played the match I need to play," said the Spaniard.
"I was playing, moving well in the beginning without mistakes, having control of the ball."
The only hitch for Roddick came right at the end of his win over Bellucci when, on his first match point, a forehand from the Brazilian was called out but overruled by the HawkEye video replay.
The umpire gave the point to Bellucci, but Roddick felt he could have played the ball and that the point should have been replayed.
Roddick continued haranguing the umpire even after clinching the win on his second match point, and later apologised via Twitter to anyone who had been offended by his outburst, which included several audible obscenities.
"Apologies for the language today folks hopefully most kids were asleep by the time I went off... my bad," read his Twitter post.
At his post-match press conference, Roddick admitted: "To be fair, I was more wrong than I thought I was out on court.
"That being said, it was very close. To take away a match point at that juncture in a match, it's a big call.
"I don't do it for entertainment. I do it because I strongly believe what I feel. That's not just on the court. I think if I believe in something strongly enough, I'm pretty outspoken about it."
Chile's Fernando Gonzalez, the 11th seed, saw off Turkey's Marsel Ilhan 6-3 6-4 7-5, but 21st seed Tomas Berdych crashed out 6-4 6-4 7-5 to Evgeny Korolev of Kazakhstan.
Twelfth seed Gael Monfils beat Antonio Veic 6-4 6-4 6-4, and 19th seed Stanislas Wawrinka swept past Igor Kunitsyn 6-3 6-2 6-2.
And in a gripping night match, 14th seed Marin Cilic twice came from a set down to see off 17-year-old Australian wildcard Bernard Tomic 6-7 (6-8) 6-3 4-6 6-2 6-4.
The match lasted three hours and 48 minutes and finished at gone 2am in Melbourne.