Roger Federer produced a remarkable recovery last night after being stunned by Russia's Nikolay Davydenko to reach his 23rd consecutive Grand Slam semifinal.
Federer moved into the last four at the Australian Open when he beat Davydenko 2-6, 6-3, 6-0, 7-5 after looking rattled and gone early in the secondset.
The world No 1 turned the match around in the space of a few minutes and went on to win 13 games in a row to shut the sixth seed out for more than an hour and easily claim the second and third sets.
But, just as bizarrely as he imploded, Davydenko gave the match another twist as he fought his way back in the fourth set.
He saved a match point with a sizzling backhand return, breaking Federer as he served for the match and threatening to take it to five sets.
Davydenko's return to form, however, came too late, as the damage had been done in an hour-long streak in which Federer won those 13 games.
At a set and a break down at 3-1 in the second set, Federer saved three break points as Davydenko failed to put away an easy backhand which would have given him a stranglehold on the match.
A rare backhand winner from Federer followed up by an ace gave the Swiss the game.
Federer immediately broke Davydenko back in the next game to put the set back on even terms and himself back in the match.
He then held his serve to 15 - the first game for the match in which he did not face a break point - and the momentum had suddenly completely swung his way.
Davydenko was now the rattled one, and a successful Federer challenge from a deep forehand gave him three break points and the Swiss raced away to lead 5-3.
Davydenko, who had beaten Federer in their last two matches, imploded in the third set as Federer raced through it unscathed.
But, as inexplicably as he collapsed, Davydenko rediscovered his game in the fourth set and made Federer work for the win.
Federer said he had to be patient after the first set. "I've played him many times and I know he goes through phases for half an hour, an hour. You've just got to stick with him and if you don't, he's going to crush you."
