Roger Federer had to come from two sets to love down to beat Tomas Berdych and reach the quarter-finals of the Australian Open.
Federer, who has won his last seven meetings with Berdych, took three hours 29 minutes to get past the 20th seed and book a last-eight date with Argentina's Juan Martin Del Potro. At one stage he looked in serious danger of failing to reach the quarters at a grand slam for the first time since Roland Garros in 2004, but he used all his experience to progress with a 4-6, 6-7 (4/7), 6-4, 6-4, 6-2 win.
The world number two got off to a poor start, dropping his serve in the opening game. He was broken again in the fifth and although he broke back immediately Berdych was able to serve out the set. The second set was much tighter with a break apiece early on leading to a tie-break, which the Czech player claimed with a simple volleyed winner to put him two sets up.
Breaks of service littered the third set but Federer made a vital breakthrough at 3-3 when Berdych, on serve, sent a backhand slice wide then smashed an easy volley into the net to give his opponent a 4-3 lead. It was all the three-time Australian Open champion needed and at 5-4 up he clinched the set with an ace. The start of the fourth set produced yet another break of serve, this time Federer got the early advantage, holding on to level the match.
In the deciding set Federer raced out to a 5-2 lead as Berdych started to falter. The world number two made a meal of serving for the match, wasting two match points, but he eventually sealed the win with two aces - his 19th and 20th of the match.
Novak Djokovic's 6-1, 7-6, 6-7, 6-2 win over the Cypriot Marcos Baghdatis started as a rout but very quickly highlighted the defending champion's struggle for form. After winning the first set with a torrent of big winners, a series of unforced errors left Djokovic 1-4 down in the second. Only a spirited recovery, in which he forced the set to a tiebreak, prevented what would have been an embarrassing reversal.
Again, it was errors that decided the third set as each game went with serve. Djokovic's tactics in the subsequent tiebreak again suggested that he is far from playing his best tennis as a series of ill-advised drop shots failed to test Baghdatis. With both players tiring – the tie break started at 1.35am – the Cypriot took advantage to win 7-5.
Yet the Serb showed admirable resolve in the early stages of the fourth and final set, as he swiftly broke Baghdatis' serve to assume a 2-0 lead as the match rolled ever deeper into the early hours. Still Baghdatis refused to lie down, forcing a break point at 2-3, only to send a careless forehand into the net. Djokovic, to his relief, pulled through what was a decisive game.
It was then Djokovic who had the chance to break, but despite having two break points, a Baghdatis ace on the second rescued him. Finally though, Djokovic's class proved too much to handle, his talent epitomised by a wonderful backhand winner on break point.
Still, however, there appeared to be no end in sight, as Djokovic surprisingly went 0-30 down. Yet any hopes Baghdatis had were soon extinguished, as the World No3 finally wrapped up the match after when Bagdhatis' forehand at the net drifted wide. So Djokovic through, but his hold on the title he won last year appears to be increasingly uncertain.
Federer's quarter-final opponent Del Potro will be playing in the second slam quarter-final of his career after beating the Croatian Marin Cilic in four sets.
For the second round in succession Del Potro had to come from a set down, eventually overcoming the No19 seed Cilic 5-7, 6-4, 6-4, 6-2. Cilic took the opening set despite a first serve percentage of just 32, but Del Potro recovered, as he had done against Gilles Muller in round three, to equal his showing at last year's US Open.
With Cilic in erratic form – hitting 48 winners to Del Potro's 27, but also making 64 unforced errors – Del Potro took his chances better in the battle of the 20-year-olds.
Both players faced 10 break points, but Del Potro converted six to Cilic's three, and, despite double-faulting on match point, kept his composure to serve out at the second opportunity.
