The 38-year-old Swede carded a closing two-under-par 70 to seal the deal by two strokes, although it was playing-partner Rafa Cabrera-Bello who had led the tournament standing on the 16th tee.
However, Stenson responded with birdies at 17 and 18 while the Spaniard could only finish tied-for-ninth following back-to-back double-bogeys.
Stenson admitted it had been tough going over the Earth Course on Sunday when he fought back from two shots adrift with just six holes remaining:
He told Sky Sports: ???It feels great but I???m exhausted. It was hot out there and a tricky day on the back nine.
???The wind picked up and I didn???t play my best. I had a shocking hole on 11 (double-bogey six) which put me back but I didn???t give up, hung in there.
???I made a couple of important par putts at 12 and 16 which kept me in the ball game then hit it to a foot on 17.
???This gave me a one-shot cushion up the last where I hit a lovely pitching wedge there to secure it.???
And he believes his escape for par at the 12th was just as important as his impressive birdie at the 17th.
Stenson went on: ???The 12-foot par putt on 12 was a big moment for me ??? after my double on 11 ??? and at 17 hit a nice 5-iron which came in a little bit off the left.
???It???s a tough pin. Rafa (Cabrera-Bello) hit a pretty good shot there but was a hair left and ended up back in the drink to make five.
???It was tough for him and lucky for me and made it easier for me on 18.???
As for collecting a first win in 12 months, he said: ???I had to hang in and wait for something to happen. I???ve had a couple of close calls this year to get my win but it wasn???t to be.
???I lost the matchplay final to Mikko (Ilonen) and was in a four-man play-off in Munich, so I???ve been close a couple of times.
???But eventually you get something if you stick around.???????
World No 1 Rory McIlroy, who fired a fourth round 68 to finish in a tie-for-second alongside Justin Rose and Victor Dubuisson, admitted: “I never expected 14-under par would have the remotest chance of winning this golf tournament.
“It just seemed like no one really took the tournament by the scruff of the neck and went with it. But then I didn’t play well enough to win this week either??and if I had won by playing like that, it would have been a bit of a surprise.???
Looking back on his year that yielded two Major titles plus two other wins and five runner-up finishes, the 25-year-old said: ???A lot of positives heading into 2015 and something I’m really pleased about this season is that consistency that I’ve shown in my golf.
???I haven’t finished outside the top 25, apart from once (at the Irish Open). My last few results have been very consistent, very good, and a lot of good stuff going into next year.
???I???ve learned a lot and I feel like I came through this year stronger and wiser, and I can go into 2015 in a much better place.
???I’m happy with the success that I’ve had and that’s a great thing going into the future.???