MILTON KEYNES, England — Hinako Shibuno of Japan wrapped up a stunning major championship debut on Sunday by rolling in a birdie putt on the 18th hole and winning the Women’s British Open by one shot over Lizette Salas.

Shibuno, 20, a Japan tour rookie who was playing for the first time outside her country, birdied five of the final nine holes for a four-under-par 68 and an 18-under 270 over all.

“I was also thinking about if I were to make this putt, how I was going to celebrate,” Shibuno said of approaching the 18th, adding: “Eat a lot of sweets.”

Largely unknown before the championship, Shibuno — nicknamed Smiling Cinderella — started Sunday with a two-stroke lead but lost it with a double bogey on the par-4 third hole. She bounced back with birdies on Nos. 5 and 7 before a bogey on No. 8 at Woburn Golf Club.