With a little help from Brown, the Big Green can still catch Yale in the Rolfe Division standings and extend their streak of division titles.
Jackson Bubala therw two scoreless innings to secure his first collegiate save while Dartmouth put three runs on the board in the third and held off the visiting Saints.
Michael Ketchmark blasted a tie-breaking three-run homer in the seventh to help Dartmouth salvage a win in the four-game series with Yale.
Freshman Rob Emery had five hits with a double and a homer, but Yale became just the second team to sweep at doubleheader from Dartmouth at Biondi Park since it was built in 2009.
Dartmouth and Yale, tied atop the Rolfe Division standings, play four games in Hanover this weekend to determine which team gets the upper hand in the race for the division title.
Dartmouth blew open the first game in the late innings to take a 9-3 victory, then pieced together four pitchers to hold Cornell to one run in a 3-1 triumph in the nightcap.
To make up a postponed doubleheader from April 3, Dartmouth is traveling to Ithaca to take on the Big Red twice on April 20.
The offense nearly doubled its season high with 15 runs and Beau Sulser threw a four-hit shutout in the opening game of the doubleheader, but Brown came back with a shutout of its own in game two.
Dustin Shirley, Michael Ketchmark and Thomas Roulis each drove in runs in the sixth inning of game two to help lift the Big Green to a 4-3 win after suffering a 4-2 loss in the opener.
Dartmouth has 15 games left on the schedule, 14 of them against Ivy League schools. The stretch begins with a trip to Rolfe Division rival Brown on Saturday and Sunday.
The Big Green had a four-run fourth, but visiting UMass Lowell had two four-run innings to hand Dartmouth an 11-6 defeat on Tuesday afternoon at Red Rolfe Field at Biondi Park.
Junior reliever Chris Burkholder is the second Big Green player to be named the Ivy League Pitcher of the Week this Year, and the first-ever for New England.