Puerto Rico's Jasmine Camacho-Quinn won her 100m hurdles semifinal in an Olympic-record 12.26 at Tokyo's Olympic Stadium on Sunday.
The 24-year-old improved her own 2021 leading time at the fan-free venue.
Jamaican Britany Anderson won her semifinal ahead of American world record-holder Keni Harrison in 12.51. Nigeria's Tobi Amusan, who finished fourth at the 2019 World Championships, won her semifinal in 12.62.
The U.S. swept the podium in Rio five years ago.
SEE MORE: Keni Harrison takes second in 100m hurdles semi, makes final