Choi calmly roll in a final putt on the 18th hole to shoot three-under-par 68 to finish just one shot ahead of current world number 1 Yani Tseng, who carded par on the final two holes to drop out of a tie for the lead.
The South Korean's fantastic final round left her with a 15-under 269 total and her first LPGA victory of the year, following an exceptionally consistent season . The 23-year-old's first place finish meant she took home the prize money of US$285,000, undoubtedly raising her position on the 2011 LPGA Official Money List. It was a tense finale for the star, who held off a fourth day charge from Taiwanese Tseng to capture her fifth LPGA Tour victory of her career.
Choi led by one stroke over American Brittany Lang after three rounds of play, and got off to an initially slow start with a double-bogey on the second hole. Birdies on 6 and 8 and two more on the back nine soon drove her back to the top of the leaderboard, ready for the tournament title battle with Tseng to commence for the second consecutive week.
The two close friends were tied at 14-under-par with two holes to play. After Tseng missed a birdie opportunity on 17, Choi hit her tee shot to approximately five feet for birdie. She sank the putt and took a one-shot lead into the final hole where she made par to complete her win.
Speaking of her victory at the Sime Darby LPGA Malaysia, the 2011 champion said: "The main thing is that I never gave up until the last hole. I feel very proud of myself on how I controlled my emotions.
"I think that I had a great experience from this week, you know, which nobody can buy; nobody can buy this experience. And actually this win marks the 100th time a Korean player has won in their career. So I won my fifth tournament and a hundred times for all of the Korean players - it's very nice, icing on the cake.
"With her victory, Choi has now tallied 10 top-10 finishes so far this year, two of which have been second place finishes, including last week's HanaBank LPGA Championship, where she fell just shy of capturing her third straight title at the event.
Choi's victory was also pertinent in that it was the 100th victory by a player of Korean descent on the LPGA Tour. The victory also serves as an early present for the young player who celebrates her 24th birthday in a few weeks.
Gracious as ever, runner-up Tseng, praised the play of her rival. The 22 year-old star said, "I played great today and I hit a lot of great shots. On the second hole I hit into the water but otherwise I hit it so good today. I knew it was going to be close but I didn't realise how close. Na Yeon played great and she made a couple of birdies on the back nine. You know, it's fun and I enjoy it, and I finished second this week which means I still have space to improve next week."
Despite falling short of her seventh LPGA Tour of the season, Tseng continues to look ahead to the forthcoming Tour events, especially competing against friend and rival, Choi.
"After that we are still good friends and I am looking forward for another week to compete with her (Choi) like this week. We just switch, last week I won and this week I'm second. So it was fun; fun to have a player like this that you can always compete with and be good friends with, too."
Elsewhere on the leaderboard, Azahara Munoz of Spain and Brittany Lang of America, currently at number 51 and 30 on the Rolex Rankings respectively (as of 10 October 2011), both fell shy of becoming first time winners today. Munoz shot a final round 69 to finish third after a strong week, and Lang shot 73 to finish in tie for fifth place with compatriot Stacy Lewis.
It was Lang's sixth top-10 finish of the 2011 season, also finishing runner up to Tseng earlier this year. For Muniz, the 2010 Rookie of the Year, it was her first top-ten finish of 2011.
Last year's inaugural champion, 31 year-old Jimin Kang was unable to relive her stellar 2010 performance finishing today's final round in four-over-par 75 to secure joint 50th place. Her performance was unfortunately in vast comparison to her finish this time last year.
Doing the home country proud, amateur Kelly Tan tied for 65th place with a fourth round score of two-over-par 73 to finish as the top amateur of the tournament. The 17 year-old student at the IMG Academy Leadbetter golf program Academy in Florida was also the leading Malaysian on the field this week.
Tan said: "Everything went well this week, and I played solid golf. There were a few holes that I didn't break. I wanted it to be a lot better and that's one of the pressures that I'm putting on myself. For me, I don't play against any of the players; I just want to play my best every single hole. If I beat the course, I beat everybody. If I beat myself, I beat everybody. I enjoyed the experience and hope to be back again on better form next year."
Unfortunately Tan's three Malaysian compatriots did not fare as well on the field. Fellow amateur Aretha Pan, who started the tournament with an encouraging performance on day one could not keep up with the pace of the world's best, finishing the week one shot behind Tan. Jean Chua and local qualifier, Ainil Johani, similarly felt the pressure on home turf finishing in 69th and 71st position respectively.