It was the 11th European Tour victory, but only the second since May 2006, for Bjorn. He finished at 14-under 274 well ahead of runner-up Alvaro Quiros, who shot 68 Sunday and was second at 278.
Rafael Cabrera-Bello also was 4-under Sunday and tied for third with Markus Brier, who started Sunday one stroke back of Bjorn but faded with four front-side bogeys en route to a 1-over 73.
Conditions at the Doha Golf Club were tough but Quiros was 4-under after 14 holes to get within one stroke of Bjorn. Quiros, however, had two bogeys and two birdies the rest of the way in while Bjorn was able to pull away.
Bjorn opened his final round with 14 consecutive pars but kept Quiros at length with back-to-back birdies at Nos. 15 and 16 -- a hole he played at 3-under on the week -- and a closing birdie.
After an opening round of 2-over 74 that included four bogeys, Bjorn had just one bogey over his final 54 holes.
Bjorn collected $411,500 for the tournament victory. Quiros won $274,336 while Cabrera-Bello and Brier each took home $139,000.