BEIJING • World No. 8 Agnieszka Radwanska might be leading calls for a shorter tennis calendar.

But the Pole is doing everything she can to make sure her season extends to the Oct 23-Nov 1 WTA Finals in Singapore.

Radwanska defeated Angelique Kerber 6-1, 6-4 yesterday to reach the China Open semi-finals. And she is now two wins away from qualifying for the season-ender for a fifth straight year.

"It's definitely been an up and down season, especially at the beginning of the year," said the fourth seed, who suggested this week for the season to end in September.

"I still have a chance to go to Singapore. I'm still fighting for that."

With her latest victory, Radwanska moved up to No. 6 in the Road to Singapore leader board. Only the top eight singles players and and top eight doubles pairs will feature in the elite field at the Singapore Indoor Stadium.

France's Caroline Garcia and Slovenian Katarina Srebotnik yesterday became the sixth doubles team to qualify.Said Garcia: "It's only the top eight teams in the world, the best of the best, so we are very proud to be there."

Slovakian Martin Klizan could not say the same about playing in the China Open, vowing never to feature at the tournament again because of the smog.

"Hazardous" levels have cleared but not before his tirade and pictures of the murky air spread on social and traditional media.

In a widely reported Facebook post, since deleted, the world No. 42 said he coughed uncontrollably and vomited after his 2-6, 1-6 loss to Fabio Fognini on Monday.

"There is such an extreme smog in this city, that due to my health... I will have to leave this tournament out from my calendar for the rest of my tennis career," the post read.

Defending champion Novak Djokovic, however, never seems to be troubled at the Chinese capital.

The world No. 1 destroyed American John Isner 6-2, 6-2 to reach the semi-finals in 52 minutes yesterday.

XINHUA, AGENCE FRANCE-PRESSE