It was the second European Tour win for Gallacher but first since he won the Dunhill Links Championships in October 2004.
He had a 1-under-par 71 Sunday, which was enough to hold off Richard Sterne, who was also 1-under in the final round. Gallacher ended up at 22-under 266 while Sterne was 19-under for the tournament. But the three-stroke difference hid the back-and-forth nature of the final round.
Gallacher opened Sunday's play with a three-stroke lead but bogeys on the first two holes and a Sterna birdie at No. 2 erased that. Both had birdies at the third hole. Gallacher had a bogey at No. 8 to lose the lead only to tie Sterne with a birdie at the ninth.
Sterne went back ahead with a birdie at 10 but returned Gallacher to the front with back-to-back bogeys at 11 and 12. They were tied again after Sterne's birdie at the 13th.
Sterne had another bogey at 15 and Gallacher holed a 110-yard shot for eagle at 16, a hole Sterne bogeyed. It was Gallacher's fifth eagle of the week.
"I've holed four shots this week but you've got to do that these days to win," Gallacher said. "You need that little bit of magic."
'How to Train Your Dragon 2' releases 5-minute clip
Yosemite climber falls 30 feet, suffers major injuries