WASHINGTON, March 7 (Xinhua) -- Former world number one Serena Williams is gearing up for her long-awaited return to a competitive WTA event at the BNP Paribas Open in Indian Wells, California on Thursday.

Williams, who has not played competitively at singles since winning the Australian Open in 2017, plays her first-round match at Indian Wells when she takes on Kazakhstan's Zarina Diyas.

The American is unseeded in the tournament this year and did not receive a first-round bye. Williams has beaten Diyas both times they've met, including at Indian Wells in 2015.

In the American's 14-month absence from the WTA actions, Williams has played just one Fed Cup doubles match when she teamed up with sister Venus Williams in the Fed Cup last month, but they lost in straight sets.

The 23-time Grand Slam winner, who gave birth in September, previously won the tournament in 1999 and 2001.