Svetlana Kuznetsova didn't show the form that saw her win the US Open, but she was good enough on Wednesday to win her opening round-robin match at the WTA Tour Championships against an erratic Vera Zvonareva.
Kuznetsova had her fellow Russian on the ropes, leading 5-1 in the second set, but lost three games in a row and squandered three match points before emerging with a 6-2, 6-4 victory.
"I was two or three weeks without matches," said Kuznetsova. "I did some mistakes. I got a little nervous that's why it happened."
Kuznetsova admitted she had expected more from Zvonareva.
"Vera wasn't playing at her best today. She played so many weeks in a row," Kuznetsova said.
Zvonareva lost on Sunday to France's Amelie Mauresmo in the final in Philadelphia -- a tournament where she needed to do well to book her berth at the elite season-ending event.
While Zvonareva made a hasty exit from the Staples Center court after the 67-minute encounter, the round-robin format means her week is not over.
All eight players play three round-robin matches with the top two from each of the two groups advancing to the semifinals.
Kuznetsova said she knows she'll have to pick up her own game to have a chance at the US$1 million winner's cheque.
"I can't make the same mistakes again," she said.
While Kuznetsova had taken a few weeks off from competition prior to appearing here, she said her life since becoming the lowest ranked, lowest seeded player to win the US Open in the Open era has been a whirlwind.
"Huge difference," she said of the changes in her life, citing increased demand for appearances both during tournaments and in her off weeks. "Free time, I don't have any," she said.
Serena Williams rallied from a set and two service breaks down on Wednesday to defeat French Open champion Anastasia Myskina in the round-robin competition.
Williams defeated the Russian 4-6, 6-3, 6-4, coming back from a 3-0 deficit in the second set with a run of eight games in a row. She put the match away with an ace on her fourth match point.
World number one and defending champion Roger Federer was grouped with Australian Lleyton Hewitt in the draw for the round-robin phase of the US$4.5 million Tennis Masters Cup season finale that starts with doubles matches tomorrow.
Federer, Hewitt, Spain's Carlos Moya and Argentina's Gaston Gaudio are in the Red Group, while American Andy Roddick, Russia's Marat Safin, Argentina's Guillermo Coria and Britain's Tim Henman are in the Blue Group.
Federer, holder of the Australian, US Open and Wimbledon titles, will no doubt be happy to avoid Henman in the opening phase. The Briton boasts a 6-3 record over the Swiss sensation.
While Hewitt leads his career head-to-head against Federer at 7-6, Federer has won all four of their meetings this year.
Singles play begins on Monday. The top two in each group advance to the semifinals.
Red Group: Roger Federer (SWI) , Lleyton Hewitt (AUS), Carlos Moya (SPA), Gaston Gaudio (ARG)
Blue Group: Andy Roddick (USA), Marat Safin (RUS), Guillermo Coria (ARG), Tim Henman (GBR)