Serena Williams thru at Key Biscayne

Key Biscayne: Playing again at No. 1, Serena Williams routed Flavia Pennetta of Italy 6-1, 6-1 in the second round of the Sony Open.Williams is playing her first tournament since she regained the No. 1 ranking at the Qatar Open. She lost the Doha final to Victoria Azarenka, but overtook her for the top ranking the week of Feb. 11.Williams trailed 40-0 in the first and fifth games in the first set, but went on to hold serve both times. In the first game, she uncharacteristically double-faulted on the first and third points. "I don't think it was too much rust," Williams said. ``I think I missed a few shots, but only because I was off footwork-wise.