Li Na continued her remarkable late-career surge by reaching the final of the WTA Championships, the tour's flagship season-ending tournament, for the first time on Saturday, making her the first Chinese tennis player to climb to No 3 in the world.
The 31-year-old did so with a convincing 6-4, 6-2 win over Petra Kvitova, the former Wimbledon champion from the Czech Republic who won the title two years ago.
Already the first Chinese singles player to win a grand slam and now assured of her highest yet season-end world ranking of at least number three, Li's latest victory suggests she is improving at an age when many players are deemed to be in decline.
Li will play an ailing Serena Williams in the final after the American struggled past Serbia's Jelena Jankovic 6-4, 2-6, 6-4.
It was not clear what was bothering Williams, but she was in obvious discomfort. She walked slowly during changeovers, did not move well on the court and frequently held her head wrapped in a towel during changeovers. Williams tried to keep the points short and often winced.
Williams, 32, and Li, 31, are the two oldest players in the elite, eight-woman tournament
Li had already commented on her age, with a mixture of irony and self-evident comment. Asked about the possibility of a final with Williams, Li said: "The oldest players have more experience on court."
She added: "This year I was feeling more, how you say, confident. I more understand what I should do on the court and off the court."
Li also seems to have managed her schedule better and certainly reserved some of her best tennis for the season's climax.
She thwarted a Kvitova comeback from 0-3 down to 4-4 in the first set by winning a long ninth game, returning serve well and always seeking to get the first good strike into the rally. In the process she saved two game points which might otherwise have created momentum for Kvitova to push on to win the first set, and Li also gained reward for pressurising the second serve when Kvitova delivered a crucial double fault on the second deuce.
Li converted that break point chance with a fine counter-hitting winner, and advanced to break serve again immediately at the start of the second set.
Although she lost that advantage, two more breaks at 3-2 and 5-2 put Li in a dominant position, and increased the uncertain mixture of winners and errors.