Venus Williams added another title to her illustrious career with victory in the final of the WTA Tour Championships in Doha on Sunday.

The American battled back from a set down to claim a 6-7 (5/7) 6-0 6-2 triumph over Vera Zvonareva of Russia.

It was the 39th title of her career for Williams, but the first for the 28-year-old in the prestigious year-ending tournament.

Both players had won all four of their previous matches in this year's tournament, but it was eighth seed Zvonareva who made the stronger start.

The Russian, who beat compatriot Elena Dementieva to reach the final, raced to a 5-2 lead in the opening set and then found herself holding four set points in game eight.

But Williams woke up at this point and reeled off a string of impressive strokes to take the set into a tie-break.

This time it was the American who surged into the lead, only for Zvonareva to claw her way back with six points in a row to take a one-set advantage.

Williams stormed back, however, with three breaks of serve allowing her to wrap up the second set to love and level the match.

Zvonareva briefly regrouped to break Williams early in the third set, but the American again stepped up a gear and responded with two breaks of her own to clinch the match in two hours and 10 minutes.

It marked Williams' sixth win in seven meetings with Zvonareva to cap a remarkable week for the seventh seed in Doha.

However, afterwards she admitted things hadn't started well.

"I played some bad shots and it went from bad to worse; before I knew it, the set was over. She just kept running everything down and hitting incredible shots.

"I realised the match wasn't over, though. I was just starting to get my rhythm, and after that I started playing better. I got a lot more consistent and was also controlling the points more. The tables started turning a little bit. I had to go out there and win the match, because she wasn't giving it away."

Williams added: "It's a fantastic feeling to end the season this way. I haven't had the opportunity to play this tournament very often, so it's really awesome to have the opportunity to play here and play well, too.

"I haven't thought too much about next year yet, but I have high and wonderful hopes for it, and at the appropriate time I'll start working hard again."

Zvonareva drew plenty of positives from her unexpected run over the past week.

"It's the first time I've got the chance to play against top-10 players five matches in a row. And I was able to come up with four wins. So, of course, it's a good week.

"I think I could have done a bit better today, played a little bit better tennis. But, overall, I'm going to try to analyse and try to be better next time."