The Canadian beat the Italian in an hour and 45 minutes, especially thanks to a 3-1 advantage to the break.
Westmount Athlete is looking for a second WTA title after Nuremberg in 2014.
Bouchard was 144thE, 10 rows shorter than Coquiretto.
Quebec won its first serve game to zero, taking a 2-1 lead with the first break.
Frustrated in the left leg, the Italian had to take care of a therapist, once leading her opponent 3-2.
At 5-2 controls after another break, Bouchard got the set when Cociarotto sent the ball into the net.
Bouchard’s third break in the second set gave him a 3-2 lead. She came back with high quality, thanks to a very deep, non-horizontal ball.
At stumps, a straight shot put Bouchard in control 5-2. The Italian sent the ball a long way, then won with the Canadian cross forehand.
In the final, Bouchard will face Sarah Soribs Tormo of Spain, who defeated Czech Maria Bouzkova 6-3, 7-6 (3) in two sets.