Justin Fowler drove in a pair of runs and Sean Sullivan singled four times, but Dartmouth could not quite come back from a 5-0 deficit after five innings.
Dustin Shirley was one of three Big Green hitters with two hits on the afternoon, but the Roadrunners rode a 5-0 lead after two innings to victory.
Dartmouth jumped out to an 11-2 lead, then held on to defeat Cal State Bakersfield for its first win on its spring break trip.
Cole O'Connor went the distance on the mound and Hayden Rappoport scored the lone Dartmouth run, but a pair of Roadrunner two-run hits did in the Green in the series opener.
The Big Green were tied at four through five and a half innings at UC Santa Barbara before the Gauchos exploded for seven runs, then cruised to a 15-5 victory over Dartmouth.
Dartmouth travels to California for a 10-game spring-break trip, beginning with a single game at UC Santa Barbara followed by a four-games series at Cal State Bakersfield.
Clay Chatham was rewarded for earning his first win in dominant fashion with the weekly award from the Ivy League office.
Clay Chatham earned his first collegiate victory by hurling eight innings of one-run ball while striking out six against the Hoyas on Sunday.
Cole O'Connor struck out a career-high 10 batters and was supported by long balls from Michael Calamari and Kyle Holbrook, but a twinbill sweep was stolen by the Huskies in a five-run ninth.
Dartmouth looks to pick up its first victory of the 2018 season and more when it plays Villanova, Northeastern and Georgetown at the Snowbird Classic in Port Charlotte, Florida.
The Yellow Jackets hit four homers in each game of the doubleheader, rallying to defeat Dartmouth in both contests, 12-9 and 11-5.
The host Yellow Jackets scored five unearned runs in the second inning and got seven shutout innings from Xzavion Curry to defeat the Big Green, 10-0.