Rose Zhang beat Jennifer Kupcho with a par on the second playoff hole to win the Mizuho Americas Open in her professional debut on Sunday, a rare feat in LPGA history.

The 20-year-old American, who was the world No. 1 amateur for 141 weeks, is the first player to win an LPGA title while making her pro debut since Beverly Hanson in 1951.

"What is happening? I just can't believe it," Zhang said after two-putting for par on the second playoff hole at Liberty National in Jersey City, New Jersey.