It was only last month that South Korean LPGA star Park In-bee decided to compete at the Rio de Janeiro Olympics, despite nagging left thumb issues that had given her reservations for weeks.

Turn the clock to Saturday, and Park is surely glad she made the call.

The world No. 5 was crowned the first Olympic women's golf champion in 116 years, with a comfortable five-shot victory over the world No. 1 Lydia Ko.

Park shot a five-under 66 in the final round to finish her four days at Olympic Golf Course at 15-under. The tournament was essentially over at the turn, with Park five strokes clear of the field. Feng Shanshan of China got to within three before falling back by five again to the South Korean, and Feng was later overtaken in second place by Ko, who birdied two of her final three holes.

Because of the uncertainty surrounding her status leading up to the Olympics, Park has been saying all week how grateful she was just to be in Rio. She repeated again and again that she never expected much of a result, and if she ended up shooting a good score, it would simply be a bonus.

And what a bonus she had.

Park hasn't played on the LPGA Tour since early June and she also skipped the International Crown, a match play competition, last month. She missed the cut at a Korean tour event just before the Olympics, which further dampened expectations that weren't all that high in the first place.

Park, however, meant business, shooting back-to-back 66s to take the halfway lead. Despite an up-and-down 70 on Friday, Park still took a two-stroke lead into the final round.

She played steady golf even in windy conditions, and the putter stayed hot from start to finish.

"I've prepared very hard for the last month to come to play this week, and I've had to overcome a lot of obstacles," Park said.

"I was able to make myself physically and mentally strong enough to compete this week. I wanted to test my limits."

Park noted that when she announced her decision to play in Rio, skeptics in South Korea wondered if she wouldn't be better off ceding her spot to another, healthier player. She said she wanted to prove them wrong here.

"I wanted to do well to show people I could still play," she said. "I am happy that I am playing right now."

She said the key to her success was fixing her swing over the last month after she'd developed some bad habits while playing through injuries.

"I wasn't swinging the way I wanted earlier," she said. "And I developed more confidence with a new swing, and that helped me create a lot of birdie opportunities here. There was still no guarantee that I'd do well here, but I wanted to test my limits no matter what the results would be. That's what Olympians do."

The Olympic title is the latest piece of jewelry on Park's already-glittering mantelpiece. The LPGA Hall of Famer Park completed her career grand slam last year by winning her fourth different major at the Ricoh Women's British Open.

Park has 17 LPGA victories, including seven majors, but said the Olympic medal "is definitely at the top" because it's a unique prize.

"It isn't something I've done before," she said. "I have won majors but not the Olympic gold medal. This is very special and nothing I want to exchange with anything else. I am so honored to represent my country, and to hear the national anthem on the golf course. It was an unforgettable moment."

With her dominant performance, Park has also earned the respect of her teammates.

"After watching her play, I became even more determined to make the next Olympic team and bite into the gold medal," said Chun In-gee, who finished tied for 13th at five-under. "I am sure she was under more pressure than anyone else. And it's incredible what she was able to accomplish under the circumstances. And because she's done that, she absolutely deserves the gold medal."

Yang Hee-young, who tied for fifth at nine-under, said she was impressed with how Park always stays on even keel, however big the moment is.

"She's always the same," Yang said. "I have nothing but admiration for her."

This was Park's first win anywhere since November, and it may also give her some much-needed boost for the remainder of the LPGA season.

Her thumb, however, remains a question mark. After her second round on Thursday, Park said she would visit a hospital after the Olympics to see if she'd be healthy enough to keep playing the rest of the season.

"I still have some lingering pain in the thumb," Park admitted.

"I didn't want it to be an excuse at this competition, though. I actually lost some distance because of that injury and made some unforced errors. I have to make sure it'll be healed completely."

Park said she has been so focused on the Olympics that she hasn't given thoughts to anything afterward.

"The priority is to be healthy again," she added. "I've been very uptight over the past month, and I feel like I have zero energy left. I need time to recharge myself." (Yonhap)