Roger Federer dug himself out of a late slump to fend off American qualifier Noah Rubin 7-5, 6-3, 7-6(3) on Wednesday and draw vital confidence for a tough third round clash against 10th seed Tomas Berdych at the Australian Open.
The 17-time grand slam champion, still finding his feet after a six-month break, had to save two set points and rally from 5-2 down in the third before closing out a galvanising win on a breezy afternoon at Rod Laver Arena.
Rubin, a 20-year-old baseline hustler with a big serve and powerful forehand, played above his 200th ranking and Federer doffed his cap to the Long Island native.
But the Swiss master said he would need to play better against big-hitting Berdych, despite winning their last five meetings, including a comfortable quarter-final victory at MelbournePark last year.
"He's caused difficulties for me in the past on faster courts: Cincinnati, New York, Wimbledon, Olympics in Athens," said Federer, whose 17th seeding ensured a demanding path to the second week.
"I know what he's got. I don't need to tell you where he's beaten me."
Federer needed time to unpick Rubin, who showed few nerves in his first match against the Swiss, but by the second set the Swiss master was cruising like a luxury car.
He served out the set to love, wrapping it up with a deft half-volley from the baseline that curled sumptuously away from Rubin as he darted across the court.
Yet barely 20 minutes later, Federer found himself 5-2 down, defending set points on serve.
The usually unflappable Swiss made a rare show of frustration, berating himself loudly as his backhand went awry.
But he saved both set points and hung tough in the next game to prise two break points from his opponent.
"Come on Rog, get up!" yelled a man in the crowd.
Federer obliged him on the second break point, hammering at Rubin's weaker backhand and the American buckled with a harried shot into the net.
Federer roared back to take Rubin into the tiebreak and raced to three match points at 6-3.
He needed only one to close it out, crushing a forehand cross-court that Rubin could only parry high and wide.
Coming back from a knee injury, Federer conceded before the tournament that he had no idea whether he was ready to withstand the long four and five-set matches of a grand slam.
He was understandably thrilled to escape with only three sets before the Berdych battle.
"If I could have signed (a contract) to be in the third round, feeling this way, weeks or days or a month ago, I would have taken it," said Federer.
"I'm still hoping to feel better and better and better as we go along.
"I'm getting tons of information out of these last few days now, which is big hopefully for the third round."