Serena Williams has reached the WTA Tour final after beating Caroline Wozniacki 2-6 6-3 7[8]-6[6] in Singapore.

Williams fought back after being 4-1 down in the deciding set to make it through to the tournament's final for the third year in a row.

Wozniacki took the first set in convincing fashion, only for the American to even it up in the second.

The Dane looked set to beat the world number one and advance to the final herself but a resilient Williams showed fighting form in the deciding set to win the tie-break 8-6.

Williams will face the winner of the other semi-final, which consists of Agnieszka Radwanska and Simona Halep.