The 28-year-old Stenson finished with a 19-under-par 269. It was his second win on the European Tour.
Stenson birdied four of the last five holes.
Second place went to Carlos Rodiles of Spain at 15-under 273. Sweden's Patrick Sjoland was third at 275.
Boston schools pull out free condoms over wrapping complaints
Aaron Carter is still in love with Hilary Duff