The Japan Open lost its two top seeds on Thursday. World No. 1 Victoria Azarenka withdrew from the event with dizziness while No. 2 Maria Sharapova lost for only the second time to No. 8 Samantha Stosur.

Stosur stunned Sharapova 6-4, 7-5(10) in a hard fought match by both players.

Stosur who was 1-10 against the Russian going into the match, led 6-4, 5-3.

“I lost nine points in a row from 5-3 up in the second set, but I knew I had to turn it around and not let that continue,” Stosur said in an on-court interview. “I had a good start in the tie-break and it really helped me forget about all of that.

“It was a close tie-break. I had some match points – if you miss a few in a row you think about it, but I stayed positive and kept going for it, and it paid off.”

Stosur closed out the match on her fifth match point.

“She had the chance to win the match easily but I made it tough for her,” said Sharapova. “I had my fair share of chances in the tiebreak.

“One point here, one point there – it just didn’t go my way. I can play a lot better tennis than I have this week.”

Angelique Kerber moved into the semifinals with Azarenka’s withdrawal.

Completing the final four in Tokyo are Nadia Petrova and Agnieszka Radwanska. Petrova took out No. 6 seed Sara Errani rallying form 3-6, 1-4 to win 3-6, 7-5, 6-3. Radwanska took out Caroline Woznaicki 6-4, 6-3.

Petrova will face Stosur in one semi and Kerber with play Radwanska in the other.

Petrova has a 5-3 record against Stosur, while Radwanska has a 3-2 edge over Kerber.

TORAY PAN PACIFIC OPEN
Tokyo, Japan
September 23-29, 2012
$2,168,400/Premier
Hard/Outdoors

Thursday, September 27, 2012

Singles – Quarterfinals
(5) Angelique Kerber (GER) d. (1) Victoria Azarenka (BLR) w/o (dizziness)
(8) Samantha Stosur (AUS) d. (2) Maria Sharapova (RUS) 64 76(10)
(3) Agnieszka Radwanska (POL) d. (10) Caroline Wozniacki (DEN) 64 63
(17) Nadia Petrova (RUS) d. (6) Sara Errani (ITA) 36 75 63

Doubles – Quarterfinals
Kops-Jones/Spears (USA/USA) d. (3) Srebotnik/Zheng (SLO/CHN) 63 62
(4) Groenefeld/Peschke (GER/CZE) d. Hsieh/Medina Garrigues (TPE/ESP) 64 75
Goerges/Zahlavova Strycova (GER/CZE) d. (WC) Pavlyuchenkova/Safarova (RUS/CZE) 16 63 105

Order of Play for Friday, September 28, 2012

Centre Court (from 13.00hrs)
1. Nadia Petrova vs. Samantha Stosur
2. Angelique Kerber vs. Agnieszka Radwanska
3. Goerges/Zahlavova Strycova vs. Groenefeld/Peschke
4. Kops-Jones/Spears vs. Lisicki/Raymond