Howard's Coldwater, Ont., rink jumped out to an early lead with a point in the second end before Jacobs' foursome from Sault Ste. Marie, Ont., tied it in fifth.
But Howard's team scored one in the seventh and added another in the eighth for a 3-1 final.
The tournament is the second men's Grand Slam event of the World Curling Tour season and had a purse of $100,000.
Howard advanced to the championship with a 5-3 semifinal victory over Toronto's Mark Kean on Saturday, while Jacobs qualified after upsetting defending champion Mike McEwen of Winnipeg 8-5.