TOKYO—Sunisa Lee became the new Olympic women’s all-around champion on Thursday, retaining in U.S.

possession a particularly coveted gold medal suddenly up for grabs after the stunning departure of Simone Biles from the competition.

Her coronation came at the conclusion of three surreal days that saw the greatest ever gymnast withdraw and completely upend expectations of how the event would unfold—and leave everyone wondering if the American women would hold on to a crown they have owned since 2004, or break the direct line of succession from household first-name stars Carly, Nastia, Gabby and Simone. .