Other source:

Goku’s female opponent proves to be a worthy contender, fueled by her anger at Goku. She says she will tell Goku who she is if he defeats her, which he does so easily. It turns out that she is none other than Chichi, daughter of the ox king, and the girl who Goku promised he would marry. Goku agrees to live up to this promise, and warns Krillin to be careful of his opponent in the next match. Realizing that Krillin is indeed strong, Piccolo agrees to show his true strength.