Having led by a single shot going into the final round he produced four birdies over the back nine holes of the course, which will stage the Ryder Cup in 2014, to overwhelm his rivals.
A closing 68 took Lawrie to 16 under par with the Australian Brett Rumford, who had led after the first round on Thursday also shooting 68. Three players - Sweden's Fredrik Andersson Hed, Maarten Lafeber of the Netherlands and Frenchman Romain Wattel - finished in a tie for third place a shot further back.
From the moment Lawrie made birdie at the 11th in his final round to move four clear of the field, they were never in the hunt.
And Lawrie even claimed he could have put the result beyond doubt far earlier in the day.
"I missed a putt on each of the first five holes," Lawrie said. "I could have been five under at the start, but I kept chugging away and showed patience. It's been the most satisfying week.
"It's been probably one of the best ball-striking weeks in my career. I putted pretty poorly today but still shot four under which showed how nicely I struck the ball.
"The course was wet and soft but I was hitting the ball long. And I am now playing the best golf of my career."
The win, following his victory in the Qatar Masters in February and seven other top 10 finishes represent Lawrie's best season since he joined the European Tour in 1992.
The 43-year-old also became the first Scotsman to win European Tour tournaments on three different courses following his Open win at Carnoustie in 1999 and Dunhill Links victory at St Andrews in 2001.
The chasing pack was bunched but Rumford, who has not won in Europe since 2007 and almost lost his playing card last year, broke free to finish second outright with two birdies in the last four holes to finish on 12 under.
- Brett Rumford
- Fredrik Andersson Hed