Serena Williams overcame the emotions which impelled her to smash a racket and earned her a code violation warning before advancing to the verge of the semi-finals of the WTA Championships in Istanbul, yesterday.

The 31-year-old American will be the oldest player ever to win the WTA title if she goes all the way, and a new champion earlier became certain when Petra Kvitova, the title-holder from the Czech Republic, withdrew, apparently with a virus.

Williams, the Olympic, US Open and Wimbledon champion, came through 7-6 (7/2), 6-3 against Li Na, the former French Open champion from China, in a tense, noisy, and surprisingly fraught affair in which she never seemed fully at ease.

Williams was 1-3 down, then let slip a break of serve, and was pegged back to 6-6 in the first set, before surviving the tie-breaker.

She then yelled and scrambled and battled her way through five deuces before winning a pivotal fifth game in the second set.

Her second win was more a triumph of will than anything else, for she landed less than 50 percent of her first serves – so often her best weapon – dropped service games five times, and needed an hour and 50 minutes before she prevailed.

Certainly Li sometimes returned serve well, and often went for broke with fierce flat-hit drives, which made it hard for Williams to achieve an attacking dominance and often forced her to scramble.

But Williams’s unease may also have been caused by lack of match play – until Tuesday she had not competed at all in the six weeks since winning the US Open.

Kvitova meanwhile was not herself during the 6-3, 6-2 loss to Agnieszka Radwanska, the Wimbledon runner-up from Poland, in their opening group match Tuesday, ending it angry and tearful.

She has been replaced by Samantha Stosur, the former US Open champion from Australia, who can still qualify for Saturday’s semi-finals if she wins the remaining two matches in the white group, against Maria Sharapova and Sara Errani.

Other result
Azarenka bt Kerber 6-7, 7-6, 6-4.