Russian Dinara Safina won a great scrap with fifth seed Serena Williams 2-6 6-1 7-6 to end the American's 17-match winning streak and reach the German Open semi-finals in Berlin.

Safina, a surprise winner over top seed Justine Henin in the previous round, made a nervous start but found her game in the second set, as Williams started to reel off unforced errors, and went on to claim another high-profile victim in two hours 10 minutes.

Ana Ivanovic, the tournament's second seed, was fighting to avoid the same fate when her match against Hungarian 10th seed Agnes Szavay was called off due to bad light.

Szavay had taken the first set 6-3 and was looking strong before the Serb snatched the second with a late break 6-4.

Safina now faces unseeded Victoria Azarenka of Belarus after she saw off the 15th seed Alona Bondarenko of Ukraine 7-6 6-2.

The winner of the match between Ivanovic and Szavay, which resumes on Saturday at 0900 GMT, will meet Elena Dementieva after the seventh-seeded Russian beat Jelena Jankovic, the fourth seed from Serbia, in an up-and-down 6-3 2-6 6-3 win.

For the second day running it was Safina who supplied the thrills, as her fightback proved too much for Williams.

The Russian looked set to blow her opponent off court as she levelled the match and went a break ahead at the start of the third.

The American broke back and saved a break point at 4-4 with a brilliant backhand pass to keep the match finely poised.

Safina then held her nerve to stay alive serving at 4-5 and 5-6 before taking the tiebreak 7-5 when a tired looking Williams put a forehand well wide on the second of two match points.

"That was one of the best matches of my life," Safina said. "The third set was tough but I was just enjoying myself so much. I knew I was doing everything right."

Williams was not too concerned about the result - just annoyed with herself for making too many unforced errors.

"I didn't play well today, in no way whatsoever," a relaxed Williams admitted.

"I could tell you 50 things I could go out there and do better. But it's better to lose when you've played badly than to lose when you've played well. I'm not going to dwell on this."

Watch the German Open all this week on British Eurosport and follow full coverage on eurosport.yahoo.co.uk.

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