In the bottom of the third, freshman Kevin Kean (Millersville, Md./Old Mill) hit a one-out triple before scoring on a double down the left-field line by junior Michael Pesci (Parsippany, N.J./DePaul Catholic). Pesci would score on a single by fellow junior Brian Klukowicz (Clifton, N.J./St. Peter's Prep).
Kean added an RBI double in the seventh that scored seniorDustin Ferguson (North East, Md./North East/Cecil CC).
Chris O'Dowd hit two, two-run home runs to lead the Big Green.
UMBC freshman starter Jon Cohn (Scottsdale, Ariz./Notre Dame Prep) (0-3) took the loss, while junior Sean Swetnam (Greenbelt, Md./Eleanor Roosevelt/George Mason) pitched 5.1 innings of relief, allowing four earned runs.
Dartmouth starter Mitch Horacek (1-0) pitched six innings, allowing two runs, to earn the win.
The Retrievers return to action Tuesday when they play at Mount St. Mary's at 3:30 p.m.