Westwood had taken command of the tournament with a stunning 65 in the third round, which featured an eagle followed by five straight birdies in a back nine of 29.
However, the 42-year-old struggled to a closing 73 after bogeys on the 16th and 17th to finish level with Thailand’s Chapchai Nirat on seven under par, before making amends with a birdie on the first play-off hole.
“Winning never gets any easier and it was a tough day out there,” said Westwood as he celebrated his 42nd professional victory worldwide. “I didn’t have the best of starts but battled back and made a couple of birdies around the turn to get more comfortable before three terrible putts on the last three greens.
“I’ve been very fortunate. As soon as I turned up five years ago I liked the course and thought it might suit my game. It’s nice to have come here three times and won three times. It’s a good hat-trick. I’ve always wanted to be a golfer that plays all over the world and I started winning on different continents very early in my career. It’s something I’m immensely proud of and (winning in) 19 different countries is incredible.”
Nirat had set the clubhouse target after seven birdies and one bogey in a final round of 66.
In Shanghai, Wu Ashun became the first Chinese player to win a European Tour event on home soil as David Howell bogeyed the 72nd hole of the Volvo China Open. Howell needed to par the par-five 18th at Tomson Shanghai Pudong Golf Club to force a play-off after Wu had set the clubhouse target on nine under par in testing conditions.
However, the former Ryder Cup player three-putted from the fringe after charging his birdie attempt seven feet past the hole to hand victory to world No 247 Wu. “Winning my national Open is very special,” he admitted. “I have many friends here with me this week, and they helped me a lot and encouraged me to play well.”
Argentina’s Emiliano Grillo, who double-bogeyed the 17th, shared third place on seven under with defending champion Alexander Levy and Thailand’s Prom Meesawat, with 19-year-old Li Hao-tong following his runners-up finish in the Shenzhen International last week with sixth place after a bogey on the last.
Two off the lead at the start of the day, Richie Ramsay’s hopes of following up his Hassan Trophy victory last month were dashed as he started with back-to-back bogeys before dropping another shot at the sixth. However, the Aberdonian battled back to card a one-over 73 to finish seventh on five-over. He picked up a cheque for more than £63,000 to sit alongside compatriot Marc Warren in the top 20 in this season’s Race to Dubai.
Howell, who had shared the overnight lead with Wu, Levy and Li, looked the most likely winner when he carded his fourth birdie of the day on the 11th to claim the outright lead, only to bogey the 14th after failing to get up and down from a greenside bunker.
That left him tied with Wu in the group ahead who had birdied the tenth and finished with eight straight pars to card a closing 71 which ultimately proved good enough for victory.
“It’s obviously tough to take,” said Howell after missing out on a chance to record his first victory since the 2013 Dunhill Links. “I was in very good shape to win the tournament for most of the day, and didn’t get the job done. So it’s going to hurt for a while, but I didn’t do a lot wrong.
“It’s obviously hugely disappointing to finish with a 6, and I guess the crucial shot was the lay-up. To miss the fairway has cost me the chance to at least force a play-off, so I’ll probably be ruing that one for a while. I actually thought I’d hit a reasonable pitch, but it came up short then I rushed the first putt past, and left myself with too much to do. But that’s golf.”
On the PGA Tour, Scottish Open champion Justin Rose was tied for the lead with Jason Day heading into the final round of the weather-hit Zurich Classic of New Orleans. The Englishman, who shared second spot behind Jordan Spieth in the Masters a fortnight ago, carded a 65 – three less than Day’s third round – for a 16-under total of 200 at TPC Louisiana.
Russell Knox, the sole Scot out of three starters to make the cut, set out on nine-under for his final round.