She used her spectacular uneven bars set — the hardest one currently being done in competition — to stay close to the top of the leaderboard.
Lee became the fifth straight American woman to claim the Olympic title on Thursday, edging Rebeca Andrade of Brazil in an entertaining and hotly contested final while defending champion Simone Biles watched from the stands.
Lee's total of 57.433 points was just enough to top Andrade, who earned the first gymnastics all-around medal by a Latin American athlete but missed out on gold when she stepped out of bounds twice during her floor routine. Russian gymnast Angelina Melnikova earned bronze two days after leading ROC to gold in the team final.
Lee, who dealt with ankle injuries so painful she was limping at times during the U.S. championships last month, actually beat Biles during the second night of the Olympic Trials at the end of June.
A month later, she found herself standing atop the podium as one of the new faces of a sport that is becoming increasingly diverse in the U.S. She is the third straight woman of color to grab Olympic gold for the Americans, joining Biles in 2016 and Gabby Douglas in 2012.
Jade Carey, who replaced Biles in the finals for the U.S. team on Thursday, finished ninth.