HANOVER, N.H. — Senior Clay Chatham handcuffed the Princeton lineup for six innings, and junior Nate Ostmo matched a career high with three hits, including a home run, to lift host Dartmouth (15-20-1, 11-6-1 Ivy) to a 6-2 victory over the Tigers (10-27, 7-14 Ivy) on Sunday afternoon, completing a three-game sweep at Red Rolfe Field at Biondi Park.

With the victory, the Big Green took over sole possession of second place in the Ivy League standings, just ahead of Columbia (11-7) with three games left in the regular season. The top two teams will square off in the best-of-three Ivy League Championship Series (ILCS), to be played the top team’s home field on May 19-20.

Chatham (2-4) surrendered just three hits, a walk and an unearned run during his stint on the mound, striking out six as the 6-6 right-hander threw 96 pitches to earn his second victory of the season.

Ostmo was part of the last four hitters in the lineup that produced seven of the nine Big Green hits on the afternoon as he went 3-for-4 with two runs and an RBI. Junior Steffen Torgersen had a pair of doubles, extending his hit streak to seven, with a run and two RBIs from the eight-hole. Both sophomore Michael Calamari (sixth) and freshman Bennett McCaskill (ninth) singled with the former scoring a run as well.

After outscoring Princeton in a doubleheader yesterday, 30-4, Dartmouth continued the scoring parade with a pair of runs in the first against Princeton starter James Proctor (0-4). Juniors Sean Sullivan and Matt Feinstein both singled to start the stanza, and after an out, senior Dustin Shirley walked to load the bases. A slow chopper to first off the bat of Blake Crossing brought home one run, and a wild pitch scored the second.

Princeton cut the deficit in half with an unearned run in the fourth after Jesper Horsted singled, stole second and took third on the throw that skipped into center field with one out. Chatham got the second out on strikes and was a strike away from escaping unscathed, but Taylor Beckett’s seeing-eye single up the middle that just went off the glove of a diving Sullivan at second base, bringing home Horsted with the first Tiger run.

In the bottom half, the offense wasted no time in responding as Calamari and Ostmo singled before Torgersen lined a double into the gap in left-center to plate both runners. McCaskill legged out an infield hit into the hole at short, and following a Sullivan sacrifice bunt and walk to Feinstein, senior Kyle Holbrook greeted reliever Andrew Gnazzo by hitting a slow roller to second to score Torgersen for a 5-1 lead.

Gnazzo pitched well in his 4.2 innings of relief for Princeton, but made one mistake to Ostmo in the fifth as the shortstop belted a 1-0 fastball over the fence in left-center for his fourth four-bagger of the season and a 6-1 advantage.

Chatham, meanwhile, allowed just one base runner in the fifth and sixth innings and struck out three along the way to finish his day on the mound with a flourish.

Princeton threatened in the seventh against senior reliever Patrick Peterson with singles by two of the three hitters, but Peterson got a pop up to second and sophomore southpaw Michael Parsons come on and got the final out on strikes.

In the eighth, Asher Lee-Tyson led off with a double against Big Green sophomore closer Austen Michel — the Ivy League ERA leader — then came around to score on a pair of grounders. That run ended Michel’s streak of 19.1 innings without allowing an earned run. But the right-hander set the side down in order in the ninth to seal the victory.

Horsted and Beckett each had two hits for the Tigers, which collected seven as a team. But those hits were not enough to keep Princeton from ending the season on a 10-game losing skid.

Dartmouth has one last mid-week contest, Wednesday at home at 4 p.m. against Middlebury, before the final series of the year at Harvard (20-19, 10-8 Ivy) beginning on Sunday, May 13. One Big Green victory would eliminate the Crimson from contention for the ILCS, but Dartmouth must win at least as many games as Columbia to beat out the Lions for the right to play for the title.

Notes: The four-game winning streak is the longest for Dartmouth since taking four straight at the end of April in 2016 … the three-game sweep is the first for the Big Green since the league switched to a three-game series format this season … Dartmouth had not scored 36 runs in a conference weekend since putting 38 runs on the board against Harvard in a four-game series in 2012 … Holbrook had a streak of 24 straight games reaching base via hit, walk or hit by pitch come to an end as the right fielder went 0-for-4 … Chatham leads the Big Green with 49 strikeouts on the mound while walking just eight … Dartmouth is still mathematically alive to host the ILCS, but would need to win all three at Harvard while Yale (14-4) would have to get swept at Penn.