No. 1-seeded Samantha Stosur posted a straight-set win Thursday in taking a quarterfinals slot at the HP Japan Women\'s Open tennis tournament. Stosur defeated Misaki Doi 6-2, 6-4 with five breaks in nine receiving games. Stosur had her serve broken once in each set but still won two-thirds of the points on serve. Marion Bartoli, the second seed, rolled to a 6-1, 6-2 win over Vania King in her second-round match. Bartoli saved all three of the break points she faced, losing just 13 points over eight service games. No. 6-seeded Ayumi Morita, the only Japanese player left in the field, moved into the quarterfinals with a 6-2, 6-3 win over Eleni Daniilidou by fighting off nine of Daniilidou\'s 11 break-point chances. Thursday\'s fourth match saw seventh-seeded Chanelle Scheepers get by Yaroslava Shvedova 4-6, 6-3, 7-6 (7-5). Stosur draws Scheepers and fourth-seeded Petra Cetkovska goes against Zheng Jie in Friday\'s quarterfinals in the top of the bracket. Bartoli faces Morita and No. 3- seeded Angelique Kerber plays defending champion Tamarine Tanasugarn in the other half of the draw.