Riding a run of brilliant late season form the fifth seeded Clijsters needed just 85 minutes to dispose of the defending champion, finishing the season with three titles in her last four tournament.

The loss was just the fifth this season for Williams stopping her just short of becoming the first woman to win $4m in a single season.

Williams, the Wimbledon, French and US Open champion, stepped onto the Staples Centre court prepared for a tough evening from Clijsters, a player who had given her problems this season.

But the Belgian began the match on an ominous note, double-faulting her opening serve on the way to being broken.

Like all her other matches, Williams, who was playing in her first event in five weeks, had difficulty finding her range committing an astounding 34 unforced errors in the opening set.

Clijsters, however, also struggled early on, both players holding serve just once in the first seven games.

The first set appeared headed for a tie-break when Williams serving at 5-6, went ahead 40-0.

But Clijsters would not wilt, breaking the American to take the first set.

Clijsters would also have the only break of the second set, surging ahead 4-2 then holding serve to collect the winner's purse of $765,000.