Top seed Justine Henin was beaten in straight sets by Francesca Schiavone in the quarter-finals in Dubai.

Henin, the two-time defending champion, went down 7-6 (7-3) 7-6 (7-4) to end a 17-match unbeaten streak at the event.

It was an unusually erratic display from the Belgian as Schiavone's exceptional court coverage and willingness to attack the net kept her under constant pressure.

Henin only created one break point opportunity - which was not converted - as the opening set stayed with serve to 6-6. She then played a dismal tie-break to hand Schiavone the set.

The unseeded Italian broke on two occasions to lead 5-2 in the second before twice failing to serve out the match.

It also went to a tie-break during which Henin again played some of her worst tennis, losing it 7-4 to crash out of the tournament.

"She played well but I didn't take the opportunities and wasn't brave enough. She was better than me, as simple as that," said Henin.

"I'm not feeling at my best level, that's for sure. I didn't go for the winners. I was playing not to lose the point instead of trying to win a lot of points.

"That makes a big difference. I had my chances to come back in the second set but I was too short.

"Especially in the tie-breaks I didn't play well at all, and she came to the net and I didn't and that made a big difference. Every short ball she was in and I didn't do the same, and that really paid off for her."

Schiavone commented: "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.

"Maybe she missed some balls, but personally I think I didn't give the possibility and the chance to come up and come up like she does every time."

Schiavone faces eighth seed Elena Dementieva in the semi-finals. The Russian defeated third seed Ana Ivanovic 5-7 6-3 6-3 in her last eight match.