Rose Zhang enjoyed a dream start to her professional career with victory in her first event in the Mizuho Americas Open.

Zhang, who only joined the paid ranks nine days ago, defeated Jennifer Kupcho on the second hole of a play-off after the pair had finished tied on nine under par at Liberty National Golf Club.

Kupcho set the clubhouse target after a closing 69 and Zhang needed to par the 18th to win in regulation, but found a bunker off the tee and was unable to get up and down from short of the green.

The 20-year-old American is the first player to win on the LPGA Tour in their professional debut since Beverly Hanson in 1951.

“What is happening? I just can’t believe it,” said Zhang after two putts for par on the second play-off hole were enough to beat Kupcho.

“It was just last week when I won NCAAs with my teammates. To turn pro and come out here, it’s just been amazing.”

Zhang confirmed she will be taking membership on the LPGA Tour which comes with the victory – after finishing her finals at Stanford and moving next week.

“I understand there is going to be a lot of bumps in the road and I’m expecting a lot of obstacles,” she said. “But I think this is just the start. This is just a stepping stone.

“It’s crazy that this is my first win, first professional win already, but no doubt there is going to be a lot more things happening down the road.

“I’m just going to be continuing to learn inside the ropes.”

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Rory McIlory had to settle for a tie for seventh.

Zhang spent a record 141 weeks at the top of the women’s amateur rankings, surpassing the previous best of 135 set by Ireland’s Leona Maguire.

She became the first women’s player to win two NCAA individual titles following her successful title defence at the end of May, a victory which saw her exceed the number of wins Tiger Woods achieved at Stanford.

Zhang also won the Augusta National Women’s Amateur in April and the US Women’s Amateur two years ago, as well as helping the United States to Curtis Cup wins over Great Britain and Ireland in 2021 and 2022.