World number one Justine Henin had her 17-match winning streak snapped at the Dubai Championship tennis tournament on Thursday when she lost 7-6 (7-3) and 7-6 (7-4) to unseeded Italian Francesca Schiavone in the quarter-finals. The Belgian top seed made a number of unforced errors as her Italian opponent ran to chase every ball.

"She played well but I didn't take the opportunities and wasn't brave enough. She was better than me," said the four-time Dubai champion Henin.

Henin held just one break point in the first set at 2-2, but made a forehand error. And she was unable to earn another opportunity, losing the tiebreak 7-3.

Schiavone broke to lead 3-2 in the second set and again to lead5-2, but she twice failed to serve out the match, despite having a match point at 5-4. But Henin once more played a poor tiebreak, losing the last four points as Schiavone took it 7-4.

Schiavone said she wasn't aggressive enough when leading 5-2.

"At that moment I didn't push hard enough and she kept going because she's so strong," said Schiavone, whose only previous win over a world number one came against Amelie Mauresmo in the Fed Cup.

"To beat Justine you have to play very good, at a high level, and I did today. I think for me it is my best win."

Schiavone will next play eighth-seeded Russian Elena Dementieva, who scored a 5-7, 6-3 and 6-3 win over third seed Ana Ivanovic of Serbia.

Russian Svetlana Kuznetsova reached the semi-finals after beating France's Amelie Mauresmo 6-1 and 7-6, and will play fourth-seeded Serb Jelena Jankovic who had the easiest of victories when sixth seed Anna Chakvetadze retired with an injury after losing the opening set 6-1.