Samantha Stosur has continued her horror run in elite level tennis finals, the top seed going down to third seed Caroline Wozniacki of Denmark in the WTA's Kremlin decider in Moscow.

Former world number one Wozniacki won 6-2 4-6 7-5 for her 20th career title and second this year to level her head-to-head record with ninth-ranked Stosur at 3-3.

Wozniacki, currently 11th in the world, broke early for a comfortable 3-0 lead.

The Australian broke back in the fifth game but failed to level as the Dane produced two more breaks to take the opening set in 37 minutes.

Stosur, the 2011 US Open champion, fought back in the second set to level at one set all after one hour 20 minutes on court.

The 28-year-old Stosur started the deciding set with an immediate break to grab the 2-0 lead but Wozniacki broke back in the sixth to level at three games all.

In the 12th game Wozniacki made the deciding break to win the set and the match in 2hr 13min when Stosur, who survived two match points, sent the ball off the court with a forehand cross.

"It was a tough match and it could have gone either ways," Wozniacki said in Russian after the match.

"You win some, I win some but that's sport," she said to Stosur.

Wozniacki received a silver Cartier trophy and a $US122,000 ($A118,250) cheque, while runner-up Stosur pocketed $US66,250 ($A64,250).

She has won just three of 15 finals contested.

The men's final between second seed Andreas Seppi of Italy and Brazilian fourth seed Thomaz Belucci will complete the tournament's schedule.