Caroline Wozniacki has fought off an extraordinary comeback from Venus Williams to win the WTA Finals in Singapore 6-4 6-4.

After a close first set, Wozniacki hit the accelerator, winning five consecutive games and serving for the set.

But Williams showed tremendous heart to fight back, winning four straight games and throwing a huge scare through the Wozniacki camp.

However, it was just out of Williams’ reach and Wozniacki won her first ever match against Williams on her eighth attempt.

Both players made a good start, running the other around the court in routine hold of serves.

Wozniacki struck first, smashing a forehand down the line to break Williams’ serve and take a 3-1 lead.

The Dane continued to hit the ball back with accuracy but Williams broke straight back and the match was on an even keel again.

Another terrific forehand broke Williams again at 5-3 but yet again the American hung in and Wozniacki was unable to put her away, and was broken back.

But several unforced errors from Williams gifted yet another break and the first set to her opponent.

From that point the momentum really swung hard towards the Dane as she closed in on her first ever win over Williams.

She broke Williams again in her first service game of the second set to take the lead, and then consolidated it to leave Williams with a lot of work to do.

But Williams began to do that work.

From 0-5 down she began a dizzying array of unbelievable tennis, sending shots every which way and leaving Wozniacki rattled.

Wozniacki argued with the chair umpire about fans yelling as she stepped up to serve and she and Victor, her father and coach, had a very long talk at a change of ends.

But it was eventually just too much for her, with an unforced error count of 32 to eight against her proving telling in the end.