With rounds of 72, 73, 65 and 69 on the par-73 Blackstone Course, the world No.8 from Seoul ended on 13 under par, a stroke ahead of the overnight leader.
“I didn’t expect that I had a chance to win this tournament, because in the second and first rounds, I didn’t play really well,” Ryu said. “Fortunately I was able to shoot eight under in the third round so after that I was in contention.
“I’m really proud of myself, because it’s good to be back in contention and our group was exciting, with Inbee and Suzann. It was good to play with Inbee, my best friend on the tour. She is not number one right now, but I believe she is the true number one, so it was great to compete with her.”
World No.2 Park, the 2014 champion, had tied or held the outright lead after each of the first three rounds and began a hot and sunny final day with a one stroke advantage. That was extended to two when Ryu three putted on the first green and then three when Ryu double bogeyed the par-four seventh hole.
Having hit left from the tee into the treacherous black lava rocks, Ryu declared her ball unplayable and took a penalty drop onto an area full of stones. She then hit her third shot over a huge bed of tall tropical vegetation into a greenside bunker and after playing a terrific sand shot, her bogey putt from five feet just lipped out of the hole.
Undeterred, the 24-year-old quickly made three birdies in four holes from the ninth and was the outright leader after 12.
Park birdied the 16th to regain a share of the lead, before Ryu again edged ahead with a birdie on 17. Both faced similar birdie putts on the par-five 18th, but could not convert them and Ryu tapped in a two feet par putt for the win.
“I missed quite a few birdie putts but Inbee wasn’t able to make a lot and the pressure was a little less, which was helpful,” said Ryu, the 2011 US Women’s Open champion, who finished third at Mission Hills in 2014. “The winning putt, no matter how long it is, is always nervous. My hands were literally shaking.”
Park said: “It was a consistent day today but my putts wouldn’t drop into the hole. It was really just the putting that was the only problem and So Yeon played well. Even with the double bogey, she played really well and I’m really happy for her. If I didn’t win, I kind of hoped that she would win, so it’s kind of good that my best friend won the tournament and I’m ready to congratulate her.”
Norwegian Suzann Pettersen and China’s Xiyu Lin shot matching final rounds of 70 to share third place on 10 under par, with Finland’s Ursula Wikstrom in fifth, a stroke further behind.
Pettersen said: “My game is slowly getting there. A few silly mistakes is costing too much in competition with these girls but overall it’s been a good week and tremendous to be back here at Mission Hills.”
Lin said: “I really hit some good shots and made some tough putts. I made a 12 yard putt on the fourth hole and eight yards from off the green on 13. Unfortunately I missed two one and a half yards birdie putts on 18 and 12, but overall I played okay. This week I didn’t expect too much so I’m quite satisfied.”
For the second consecutive year, Ryu and Park were the runaway winners of the team event for pairs, representing South Korea. With an aggregate total of 559, they ended 15 strokes ahead of Norwegians Marianne Skarpnord and Pettersen.
For China’s rising star Lei Ye, who finished in 55th place to claim the leading amateur prize, the whole event was a learning experience.
The 13-year-old, who attends international school in Shanghai, said: “I played really well the first day and that gave me more room to make the cut. I’ve noticed from playing in professional tournaments that putting is my weakness. I hope to improve and turn professional someday.”
The next Ladies European Tour event is the Lalla Meryem Cup which takes place on 26-29 March in Agadir, Morocco.
279 – So Yeon Ryu (KOR) 72 73 65 69
280 – Inbee Park (KOR) 69 69 71 71
282 – Xiyu Lin (CHN) 71 68 73 70, Suzann Pettersen (NOR) 73 72 67 70
283 – Ursula Wikstrom (FIN) 74 72 68 69
285 – Pamela Pretswell (SCO) 73 72 69 71
286 – Shin-Ae Ahn (KOR) 71 74 71 70
287 – Rebecca Artis (AUS) 72 72 69 74
288 – Holly Clyburn (ENG) 74 65 74 75
291 – Yu-Ling Hsieh (TPE) 75 74 71 71
292 – Becky Morgan (WAL) 69 74 73 76, Pei-Yun Chien (TPE) 74 72 70 76, Marianne Skarpnord (NOR) 77 73 72 70
293 – Melissa Reid (ENG) 73 74 71 75, Nontaya Srisawang (THA) 71 73 73 76, Marion Ricordeau (FRA) 76 73 72 72
294 – Ssu-Chia Cheng (TPE) 73 73 72 76, Nicole Broch Larsen (DEN) 74 70 77 73, Caroline Martens (NOR) 75 74 71 74, Vikki Laing (SCO) 75 72 75 72, Valentine Derrey (FRA) 75 72 72 75