The Swede ended the tournament 16 under par to successfully defend a title for the first time in his career - finishing two strokes ahead of Victor Dubuisson, Rory McIlroy and Justin Rose.
Victory saw Stenson claim second place behind McIlroy in the Race to Dubai, and Stenson revealed the season-ending tournament had taken its toll.
"It feels great [to win the tournament]," he said. "I'm exhausted to say the least.
"It was hot out there and tricky on the back nine. I did not play my best and had a shocking hole on 11 which knocked me back, but I did not give up.
"I just had to dig in there and wait for something to happen.
"I had a couple of close calls this year to get my win and it was not to be. It's been close, but eventually you get something if you stick around and I surely did that."
McIlroy - trailed by Stenson, Justin Rose, Jamie Donaldson and Dubuisson in the Race to Dubai's top five - bemoaned his failure to take control of the tournament this weekend.
"It seemed like no-one took it by the scruff of the neck and I thought if I could post 16 under I might have a chance," he added.
"I just did not play well enough to win this week."