Louisville trailed 17-2 to start the game but stormed back behind 20 first-half points from senior Tia Gibbs, who finished with 23.
The Cardinals (4-0) then led by double digits before the Sooners came storming back.
Louisville trailed by six with just over two minutes left but Jude Schimmel scored the final four points of regulation to tie the game.
In overtime, U of L opened a 95-87 lead before Oklahoma scored five straight points. Asia Taylor then pulled down a rebound and hit two free throws to seal the victory for the Cardinals.
Shoni Schimmel scored 16 points for the Cards, while Taylor finished with 10 points and 10 rebounds. Sara Hammond had 13 points and seven rebounds and was named WNIT MVP.