U.S. Open winner Svetlana Kuznetsova avoided a second-set collapse and held on to defeat Russian countrywoman Vera Zvonareva6-2, 6-4 in round-robin play.

Lindsay Davenport, the world number one, faced Elena Dementievain the late match.

Williams overcame 61 unforced errors to improve to 4-0 lifetime against Myskina. The Russian had never taken a set from Williams in three previous meetings.

Myskina led 3-0 in the second during a stretch when Williams won just three points in four games, including the last game of the first set.

Trailing 3-0, Williams reeled off eight straight games over the second and third sets. She was ahead 2-0 in the third when Myskina won three consecutive games to take a 3-2 lead. Williams staved off three break points to hold at 3-3. She broke Myskina in the next game and held at 5-3.

Myskina held to trail 5-4 before Williams needed four match points to close out the victory. They two combined for 102 unforced errors and just 53 winners in the two-hour match.

Williams won the tournament in 2001 and lost in the 2002 final.

Kuznetsova blew most of a 5-1 lead in the second set when there were seven service breaks. Zvonareva won three straight games to trail 5-4.

Kuznetsova set up her first match point with a forehand winner.On her second match point, she pulled a backhand wide, then netteda forehand to get to deuce. Kuznetsova smacked a huge forehand for her third match point, before sending a forehand long for deuce.

Zvonareva netted a forehand to set up the fourth match point, then missed a backhand to end the match.

Zvonareva managed just one break point on Kuznetsova's serve inthe first set. She slammed balls and her racket on the hard court several times without penalty and departed after the match without talking to reporters.

The players are assigned to Red and Black four-woman groups and play each other once. The two players with the best record from each group advance to Sunday's semi-finals. The singles winner will earn 1 million US dollars and a car to donate to charity.

Both Kuznetsova and Zvonareva, among five Russians in the eight-player field, are making their debuts in the season-ending championships.