New world number one Caroline Wozniacki overcame worries about a knee injury to reach the China Open women's final on Saturday while Novak Djokovic moved within one step of reclaiming the men's title.
On another smoggy day at the Olympic Tennis Centre, world number two Djokovic, the top seed, beat tall American John Isner 7-6 6-2 to reach the men's final, where he will play Spain's David Ferrer. Ferrer defeated Croatia's Ivan Ljubicic 6-4 4-6 6-4.
Djokovic's victory ensured his qualification alongside world number one Rafael Nadal and number three Roger Federer for the ATP World Tour finals in London next month.
Wozniacki, who replaced Serena Williams as the women's world number one earlier this week, defeated Israel's Shahar Peer 7-5 6-2 in her semi-final.
The Dane, who played with a strapped knee after an injury scare in the quarter-finals, will meet second seed Vera Zvonareva in Sunday's final.
"My knee felt better today than it did yesterday," said the 20-year-old Wozniacki who is seeking her sixth title of the season. "I've had a lot of treatment on it. I still felt it a little bit but it's not getting worse, so that's a positive thing."
Russian Zvonareva, the world number four, dashed China's hopes of having a home representative in the final when she beat ninth seed Li Na 6-3 6-3.
"I think Li was going for lot of risky shots so she suffered unforced errors," Zvonareva said.
I knew I just had to hang in there and try to counter-punch her if I got the chance. I think I did that well."
Serbian Djokovic dominated in the second set against the 2.06-metre Isner who struggled to return.
"I knew the key to winning today was to return well and get him into the longer rallies," Djokovic said. "I didn't allow him to get into the middle of the court and near to the net to take control."
Smog crept across the showcase courts as monitors on top of the United States embassy in Beijing rated the air as hazardous for the fourth day in a row.
Tournament organisers have played down health concerns posed by the smog but Djokovic told journalists on Friday that the air quality made it hard to recover from rallies.
