Williams tests injured knee by doing the splits

By Julian Linden SINGAPORE (Reuters) - World number one Serena Williams erased any concerns about her dicky left knee with a 6-4 6-4 win over Ana Ivanovic at the WTA Finals on Monday that featured two eye-popping demonstrations of her flexibility. Never one to do things by half, Williams provided a startling exhibition of just how much her troublesome knee has improved since she pulled out of two events in China. Tentative at the start, Williams quickly got into stride. Midway through the first set, she sprinted so hard to try and chase down a forehand from Ivanovic that she ended up doing the splits. The crowd gasped in wonder as she bounced back up to her feet like an Olympic gymnast. Then she did the splits again in the second set, showing she has the elasticity to compliment her renowned power. "I do work on my flexibility, but not for tennis, because I dance," she later told a news conference. "I guess it comes in handy. Like knocking two birds out with one stone." Her acrobatic display was enough to alleviate any concerns about her prospects of winning the WTA's lucrative championship for a third straight year. A few weeks ago, her chances of winning looked slim after she first quit the Wuhan Open because of illness then the China Open with a knee complaint. The world number one only resumed training last week, restricting her practice to reduce any risk of aggravating the injury but showed no lingering effects against the lightning-fast Ivanovic, thumping down a dozen aces in her opening match. "I didn't have any fear at all. I felt pretty good," said Williams. "I felt the knee a little bit, but compared to what it was in Beijing, it feels so much better. "I'm getting better, which is great. Just have to keep doing my program so by the end of the week, hopefully -- if I'm here -- I'll still be getting better." If Williams had any health concerns after the match, it was with her voice, not her knee. After blowing a 4-1 lead in the opening set and allowing Ivanovic to get back to 4-4, her relief at taking the set was clearly visible. She clenched her fist and yelled "C'mon" -- and repeated the gesture so many times before the end that she finished with a croaky throat. "It's definitely all reflex. I never do it on purpose," Williams said. "I felt like my energy got a little low, and then I just tried to do everything I could to bring my energy level up or just to fight. "Because if I'm not playing well, I have to rely on other things. So then I think at that point, that's when the match really turned and got super intense." (Editing by Patrick Johnston)