Serena Williams thrashes Agnieszka Radwanska to enter China Open final

World number one Serena Williams powered through her semifinal match with Poland's Agnieszka Radwanska 6-2, 6-2 to advance to the final of China Open on Saturday.

The American 32-year-old pulled up injured after appearing uncomfortable in the fourth game of the third set, clutching her back as she walked off court with medical officials.

But the brief pause did not result in Serena losing her momentum, as she ruthlessly finished off the third seed in convincing style, breaking serve in the next game before closing in on victory.

The top seed in Beijing said she had not picked up any serious injuries during the match.

"My back was a little tight from playing a lot so I was just trying to release it," she said.

"Its been a little tight all week and it just spasmed a bit out there today."

Serena will face eighth seed Jelena Jankovic in the final after the Serb defeated Czech Petra Kvitova following an early scare.

Jankovic lost the first set on a tie-break, but the world number 11 dominated the following sets, losing only two games to crush Kvitova 6-7 (7/9), 6-1, 6-1.

The final will take place on Sunday.