De La Rosa was UMBC's America East Player of the Game with 18 points and six assists. Terrier junior forward John Holland earned the honor for the visitors, hitting five-of-six behind the arc in a 25-point, 12-rebound performance.
Holland opened the second half with a three-pointer to extend a 14-point halftime lead to 40-23 just 15 seconds into the stanza. But UMBC went on a 19-7 run and closed the gap to 47-42 after Robbie Jackson (Aberdeen, Md.) converted a pair of free throws with 11:41 remaining.
But Jackson was whistled for a blocking foul as he attempted to take a charge on the ensuing possession and Holland converted both free throws. UMBC missed jump shots on the next two trips, while Holland buried a three-pointer and then hit a 15-foot jumper to restore the margin to 54-42 with 10:03 remaining.
The Terriers extended the run to 17-1 and led 64-43 with 6:10 remaining.
UMBC started the game cold and never warmed up in the first 20 minutes. The Retrievers missed 15 of first 19 shots from the floor, and only hit 9 of 32 from the field. Boston, which averages 8.3 three-point field goals per game, hit eight of 16 in the first half and four different Terriers hit shots from behind the arc.
The visitors closed the half on a 12-4 run and led, 37-23, at intermission.
UMBC freshman Adrian Satchell (Windsor, Conn.) scored seven points and tied his season high with 10 rebounds. Sophomore wing Chauncey Gilliam (Columbia, Md.) was the other Retriever in double figures with 10 points and he helped create several Terrier turnovers (16) by tying a career-best with four steals.
But the Retrievers shot only 35 percent from the floor, while the Terriers hit 15 of 23 shots from the floor (65 percent) in the second half and were at 55 percent (28 of 51) for the contest.
Boston sophomore post Jake O'Brien added 18 points for the visitors.
UMBC completes its three-game homestand vs. Binghamton on Wednesday, Jan. 28.