Doha, Qatar -- Serena Williams defeated her sister Venus Wednesday at the Sony Ericsson Championships and also learned she would end the year as the No. 1 player in the world.
Williams went into the season-ending event ranked second behind Dinara Safina and needed to post more victories this week than Safina to pass her and claim the top spot. Safina, however, retired from her opening round-robin match Wednesday and gave up a chance to end the season as No. 1 for the first time in her career.
It is the second time Williams has concluded a season ranked on top. She also did so in 2002.
