Spotless Serena, Li Na sail into semifinals

Li Na rolled past a visibly struggling Victoria Azarenka at the WTA Championships to advance to the semifinals from the White Group here on Friday.

The Chinese’s crushing 6-2, 6-1 victory over the second-seeded out-of-sorts Belarussian also enabled Jelena Jankovic make the cut for the last-four stage in the year-end bash.

Li looked very sharp from the outset, her serve, groundstrokes and volleys hitting their mark time and time again as she stormed out to a 3-0 lead. Azarenka temporarily stopped her momentum, squeaking out two games in a row to close the gap to 3-2, but from there she was visibly struggling with an injury, and the fourth-seeded Li pounced with eight games in a row for a 6-2, 5-0 lead.

 Azarenka scrounged up a hold of serve, but Li quietly served it out at love in the next game for a smooth win.

“I know this is not the best way to win the match,” Li said in her on-court interview afterwards. 

“I saw her a little bit bothered with her back but she kept playing, so it was very tough for me mentally.

“"If she were healthy she would have been a very tough opponent today. Unfortunately she wasn't healthy. I have to enjoy this moment, but I hope the injury isn't too bad and she can come back soon.”

Serena Williams outslugged Petra Kvitova to become the first player to enter the semifinals on Thursday evening after the American crushed Petra Kvitova 6-2, 6-3 to complete her stroll through the Red Group.

World No 1 Williams, looking to retain her title, has won all three matches at the Sinan Erdem Dome without a dropped set, leaving her rivals to scrap over the runners-up spot in the section.

Kvitova, however, didn’t allow the pummelling to get the better of her, the Czech exhibiting good tenaciousness on Friday to beat Angelique Kerber 6-7, 6-2, 6-3 to seal the fourth and final semifinal spot.

Del Potro shines

Defending champion Juan Martin del Potro claimed his 300th match win as he cruised into the Swiss Indoors semifinals with a 6-4, 6-4 win over qualifier Paul-Henri Mathieu at Basel on Friday. 

The Argentine dominated on serve, hitting 11 aces and only surrendering six points overall to claim victory in 79 minutes.

Del Potro has already secured his place at the season-ending ATP World Tour Finals and is bidding to win his fourth title of the season and reach his third final in a row. The Tandil native is coming off a strong Asian swing, which saw him win the Japan Open in Tokyo and defeat World No 1 Rafael Nadal to reach the Shanghai Masters final.

Del Potro next will face World No 65 Edouard Roger-Vasselin, who reached his third ATP semifinal of the season as he as he battled past Daniel Brands 6-3, 4-6, 6-3. The Frenchman withstood 14 aces and saved four of the five break points he faced to prevail in just under two hours.

Rising Canadian star Vasek Pospisil took another step forward on Friday as he defeated Ivan Dodig 7-6 (13-11), 6-4 to reach his third ATP semifinal of the season. 

The 23-year-old relinquished a break advantage in the second set, but broke decisively in the ninth game before serving out victory in one hour and 45 minutes.