Tennis: Keothavong and Baltacha both fall at the second hurdle in Melbourne

The 27-year-old started well but ran out of steam against 30th seed Andrea Petkovic, eventually going down 6-2 5-7 0-6 in round two.

Defeat was hard on Keothavong who made her higher-ranked opponent look distinctly ordinary for a set and a half before Petkovic finally found her range.

The Londoner said: "No doubt I had my chances in this match. For a set and a half I definitely felt I was playing some good tennis.

"I really did what I intended to do out there and took my game to her and was hitting out a bit more.

"But it got close and I felt like I had to win that match in two sets.

"I've played Andrea before. When she's got a bit of momentum and confidence she's a tough player to pin down."

Elena Baltacha's Australian Open adventure also came to an end despite a battling display against 11th seed Justine Henin.

Henin, one of only two previous champions at Melbourne Park in the draw, was made to work hard by the British No 2 in their second-round match, particularly in the second set, but came through 6-1 6-3 in 61 minutes.

Roger Federer finally overcame his nemesis Gilles Simon although it took him five sets to reach the third round.

Simon went into the contest having beaten the world No 2 on their previous two meetings and he looked set to cause another huge upset when he hit back from two sets down to take it all the way. But the Swiss, defending champion in Melbourne, upped the tempo to squeeze through 6-2 6-3 4-6 4-6 6-3 and avoid his first exit at a grand slam before the third-round stage since the 2003 French Open.