DOHA, Qatar - The Williams family rivalry resumed at the Sony Ericsson Championships - Doha 2009 on Wednesday, and for the third time in a row it was Serena Williams who prevailed, saving match point in the third set and edging Venus Williams.  Doha: Wednesday Highlights

Watch live tennis from Doha all week on TennisTV.com!

Serena, the No.2 seed, lost the first set to No.7 seed and defending champion Venus, 5-7, but rebounded to take the second set, 6-4, and built a two-break, 4-1 lead in the third. Venus found her range again, winning five of the next six games to lead, 6-5, even holding a match point; but Serena played with all-out aggression on that point, following several down-the-lines up with a massive overhead. She won, 57 64 76(4).  Highlights: S.Williams vs. V.Williams

"It really could have gone either way. At the end of the third set she just started playing great," Serena said. "I was just trying to do what I could. I kept saying, 'I want to end this year No.1, so I'd better lift up the level of my game.'"

"Today was a close match. I definitely would have liked to win," Venus said. "It was almost three hours. I came close to winning. I feel like I played one loose point in the tie-break. I remained aggressive. It was kind of by one point..."

Check out the best action pics from Wednesday's matches in the gallery!

The Williams sisters' first match of the year came in Dubai, where Venus won to go ahead 10-9 in the rivalry; but Serena has won three in a row since then, at Miami, Wimbledon and now here, to surge ahead in the series, 12-10.

By virtue of Dinara Safina's withdrawal, Serena also secured the year-end No.1 ranking, which was relayed to her during her post-match interview.

"It was definitely a surprise," Serena said. "I didn't know. I just wanted to win so badly because I figured Dinara was hurt and if I could just win a few matches, I could finish No.1. I didn't know she pulled out. I just wanted to win."

Serena will finish a season at No.1 for the second time in her career, having achieved the feat in 2002 as well.

Read more about matches from earlier in the day...
Caroline Wozniacki d. Victoria Azarenka, 16 64 75
Jelena Jankovic d. Dinara Safina, 11 ret. (low back injury)