The victory was the fifth straight for the Yellow Jackets (9-2) and improved their record at new McCamish Pavilion to 7-0.
Miller, just missing a double-double, had nine rebounds and Mfon Udofia added seven assists.
Georgia Tech shot 55.5 percent in the second half (16 of 29) and 50 percent for the game (29 of 58) despite a slow start.
Gaston scored Fordham's first eight points of the second half, but Georgia Tech went on a 21-2 run to turn a 41-35 lead into a 62-37 advantage with 8:15 left.
The last 17 points came in a row, with seven players scoring.
Fordham defeated Georgia Tech 72-66 last Dec. 29 in New York as Gaston had 23 points and 17 rebounds, and Frazier contributed 19 points and six assists.
Frazier's three straight 3-pointers gave Fordham a 14-13 lead with 8:09 remaining in the first half. But Georgia Tech quickly got the lead back on a basket by Carter and the Yellow Jackets' advantage was 35-25 at halftime.
Jason Morris, who had missed the previous two games because of plantar fasciitis, hit two of the Yellow Jackets' three 3-pointers late in the half after Georgia Tech had started 0 for 6 from behind the arc.
Carter and Miller each had eight points in the first half for the Yellow Jackets. Georgia Tech started the game 4 for 15 from the floor, but closed the first half making 9 of 14 shots.
Frazier, the Rams' leading scorer at 16.8 points per game, had 10 at the break, but the Rams shot just 28.6 percent (8 of 28). Gaston, who entered averaging 14.3 points, made just 1 of 8 shots and had four points.
Georgia Tech hosts Chattanooga on Wednesday in its final nonconference game before beginning Atlantic Coast Conference play next Saturday at home against Miami.
The Yellow Jackets' two losses came at No. 12 Illinois and against California in the DirecTV Classic in Anaheim, Calif.
Fordham, which had won two of its previous three games, plays Monmouth at home on Monday in a nonconference game.