Dulaney senior guards Isaiah Lamb and Scott Harrelson combined for 46 points to lead Dulaney (5-2) past host Mount St. Joseph (12-3), 69-63, Friday night in Irvington.
Lamb led the Lions with 25 points and added nine rebounds and Harrelson finished with 21 points.
"It takes a total team effort and tonight we had a total team effort," Dulaney coach Matt Lochte said.
"Lamb is a very good player and Harrelson is a tough, verstatile athlete," Mount St. Joseph coach Pat Clatchey said.
Harrelson had 17 points and Lamb had 13 at halftime as the visiting Lions built a 38-21 lead.
Randy Miller (team-high 18 points) and Doc Barnes (9 points) kept the Gaels within striking distance with 16 (8 each) of the Gaels 21 points at halftime.
A three-point play by Lamb with 3:22 left in the third quarter gave the Lions its largest lead of the game, 57-31, before the Gaels mounted a comeback.
A basket by Miles Wilson (8 points) cut the margin to 64-54 with 3:20 left, but Lion senior Jimmy Bonner answered with a three pointer to stem the tide.
"It takes something to take that shot and then hit it down and when it drops it puts everybody at ease," said Lochte of Bonner's only points of the night.
The Lions also got contributions from senior forward Jair Williams (11 points) and point guard Gary Bernardez (5 points, 9 rebounds).