Serena Williams beat Estonia's Anett Kontaveit in the second round of the U.S. Open to set a record, ESPN reported.
The 23-time Grand Slam winner and former world number one has become the first woman tennis player in history to defeat a top-three WTA player at age 40.
Serena Williams defeated world No. 2 Kontaveit 7-6 (7-4), 2-6, 6-2. Her next opponent will be Ajla Tomljanovic of Australia.