Serena Williams reaches round of 16

NEW YORK, Sep 4 (Reuters) Serena Williams showed herself to be a serious contender despite her year of inactivity by trouncing 16th seed Ana Ivanovic of Serbia 6-2 6-4 to reach the US Open fourth round.

Williams, playing just her fourth tournament of 2006 after struggling with a knee injury, needed just 66 minutes to beat 18-year-old Ivanovic, who won the Montreal hardcourt tournament this year.

Seven-times grand slam winner Williams issued a wildcard into the tournament and currently ranked only 91 due to her absence from the tour, was broken just once in the match.

Twice Open winner Williams, 24, will meet either top seed Amelie Mauresmo or unseeded Mara Santangelo of Italy in the round of 16.

Reuters DH GC0520