What appeared to be a rookie mistake in the 4x400-meter mixed-gender relay jeopardized Team USA's shot at a gold medal.
Americans coasted to the win in the first qualifying heat of the event, but the four sprinters were disqualified when it was ruled that a baton handoff between Elija Godwin and Lynna Irby took place outside the exchange box before Irby ran the second leg.
After USA Track & Field appealed the ruling, the team now says the disqualification has been overturned, meaning the gold is still within reach.
"The U.S. 4x400m mixed relay team has been reinstated and will compete in Saturday's final," the team announced after a few hours of online scrutiny over the simple but costly error.
It's not yet clear whether Irby lined up at the wrong place or it was a mishap caused by track officials.
But Irby's coach, Lance Brauman, told The Washington Post that the blame rests with a race official who he claims lined her up in the wrong spot: "It wasn't her fault that they made the mistake, and she ran very well," he said.
Fumbled passes have long been a hurdle for Team USA in track events, but baton blunders are more common in the shorter 4x100 event in which sprinters are challenged to make deft passes more quickly than in the 4x400.
It wasn't until a post-race interview with the quartet that the sprinters learned they had been disqualified.
A shocked Irby appeared caught off guard as she processed the news relayed by a reporter. "OK, I mean that's disappointing, but lessons learned," she said.
But she kept her composure until after the interview when she broke into tears.
Now that the U.S. is cleared to run in Saturday's 4x400m mixed relay final, Allyson Felix, who is expected to run in the event, has a shot at clinching a record 10 Olympic medals. Felix is one medal away from becoming the most decorated Olympian in women's track and field history.