Dyami Starks scored all 17 of his points in the second half, including a tiebreaking driving basket with 1:44 to play, lifting Bryant past Boston College 56-54 for the school's first victory ever over an Atlantic Coast Conference team.
Frankie Dobbs added 15 points and Corey Maynard nine for Bryant (3-2), which moved to Division I four years ago and had lost all four previous meetings with the Eagles. The Bulldogs had been 0-5 against ACC teams.
Olivier Hanlan led Boston College (2-4) with 19 points and Joe Rahon had 11.
After Boston College tied the game on a jumper by Hanlan, Starks did what he did for most of the second half - he hit a key basket for Bryant.
Alex Francis' free throw gave Bryant a 54-51 edge before Rahon had one free throw for the Eagles.
Dobbs then hit the first of two from the line, making it 55-52, before the Eagles' Hanlan hit two from the line with 31 seconds left.
Hanlan missed a short jumper in the lane and the Eagles fouled Dobbs, who hit one of two to make it 56-54 with 12.5 seconds left.
Boston College called time out at midcourt and Hanlan was called for an offensive foul with 3 seconds left, but the Bulldogs' inbounder traveled before throwing the ball in, giving the Eagles one last shot.
Ryan Anderson's long jumper rolled off the rim and the ball hit the floor as the horn sounded.
Trailing 49-45, Dobbs and Starks nailed consecutive 3s just 32 seconds apart, giving the Bulldogs their first lead since early in the second half.
But Hanlan's long jumper from the top as the shot clock was about to expire tied the game at 51-51 with 3:23 to go.
The Eagles, coming off a one-point win over Auburn on Wednesday, went on a 16-5 run early in the second half to grab a 40-34 lead on Andrew Van Nest's two free throws with 12:48 to play. Hanlan started the spree with three straight driving baskets - he was fouled on the first and converted the free throw for a three-point play.
The Bulldogs are coached by Boston College grad ('84) and longtime assistant Tim O'Shea.
In a first half filled with mostly missed shots, Bryant held a 26-24 edge at intermission after Maynard's driving buzzer-beating shot in the lane.
Boston College missed its initial seven shots from the floor and Bryant 7 of 8. The teams then posted similarly ineffective 2-for-11 and 3-for-15 marks from the field before they started to heat up a bit before the half.
Lonnie Jackson and Rahon had consecutive 3s from the left corner 36 seconds apart late in the half, giving the Eagles their first lead of the game, 22-21, before the Bulldogs scored on their last two possessions. Dobbs nailed a 3 from the right wing prior to Maynard's basket.