The fifth-seeded Frenchman defeated his compatriot and national number one in under an hour and a half as Gasquet surrendered the ATP 250 title he won a year ago.
Top seed Gasquet's service game was accurate - with 75 per cent of first serve landing in - but he registered no aces as Monfils won points on 38 per cent of them.
A single break point was enough to put Monfils in the ascendancy in the first set, which he served out with a crunching ace.
The first game of the second set saw Monfils carve out three break points, but Gasquet saved them all in an epic 13-minute opener.
At 4-4, Monfils hit three straight points to turn a 40-15 score in Gasquet's favour into a chance to serve for the match.
And he served out to love to secure a straight-sets victory and his fifth career title.