CAMBRIDGE, Mass. — The Dartmouth Big Green completed a four-game sweep of Harvard on Sunday afternoon at O’Donnell Field, beating the Crimson by scores of 4-2 and 9-4. The two victories give Dartmouth 31 wins for the season, breaking the school record of 30 set just two years ago. Overall the Big Green are 31-7 and finished Ivy League play with a 15-5 mark and their sixth straight Rolfe Division title, which it clinched yesterday.

Dartmouth will play in the best-of-three Ivy Championship Series next weekend at Columbia, which posted a 16-4 record in the conference to earn the right to host the event. The two teams will play a doubleheader on Saturday and a single game on Sunday if necessary.

Harvard’s season came to a close with the two losses, ending the year at 10-30 overall and 7-13 in the Ancient Eight.

Junior Mitch Horacek (6-2) went the distance in the seven-inning, 4-2 victory to start the day. The left-hander surrendered the two runs on just four hits and a walk while fanning four. Three times he retired the side in order, including the seventh to finish off his third complete game of the year.

It was Harvard that struck first, however, as Matt Sanders reached on a two-base throwing error with one out and Carlton Bailey brought him home with a sharp two-out single to left for a 1-0 Crimson lead.

Dartmouth answered immediately in the top of the fourth. Junior Jeff Keller opened the inning with a single to right-center, then took second on a wild pickoff attempt. With one down, freshman Joe Purritano sent a pitch back through the box for an RBI single to tie the score. After a single by sophomore Nick Lombardi, sophomore Bo Patterson hit a chopper to short that crawled up the fielder’s arm and into left field for a two-base error, allowing Purritano to score the go-ahead run. Sophomore Matt MacDowell then bounced an RBI grounder to second for a 3-1 lead.

In the fifth, the Big Green got another unearned run when they put runners on first and second with one down and junior Dustin Selzer hit a grounder just inside the foul line. The third baseman scooped up the ball, stepped on third for the force but unleashed a throw over the first baseman’s head that went well down the right-field line, bringing Keller all the way home from first.

Harvard got that run back in the sixth after the first two hitters were retired. Mike Martin beat out an infield hit, then scampered home on a Brandon Kregel double into the left-center gap. Nick Saathoff followed by stroking an 0-2 pitch up the middle, but second baseman Shane Ogren made a nice back-handed play and got the third out at first to keep the Dartmouth lead at two runs.

Sophomore Matt Parisi had two of the Big Green’s six hits in the game, while Keller scored two of the four runs.

Taking the loss was Tanner Anderson (2-5), despite yielding just one earned run in seven innings. He allowed six hits and did not walk a batter, striking out a pair.

In the nightcap, Crimson starter Baron Davis did not allow a hit until two were out in the fifth and enjoyed a 1-0 lead through five frames courtesy of a first-inning run. Anderson, playing second base after his pitching duties in game one, lined a two-out single to score Martin, who had walked and stolen second base.

The Big Green bats started to wake up in the sixth with Purritano tying the game with an RBI single and Lombardi giving Dartmouth the lead with a sacrifice fly. The flood gates opened in the seventh, though as senior Chad Piersma led off with a double to deep right-center. After a strikeout, Parisi single Piersma to third and knocking Davis from the game. Parisi stole second on reliever Jordan Haviland before senior Ennis Coble walked to load the bases. A deep fly ball to left off the bat of Keller allowed Piersma to score and Parisi to take third, and Coble then stole second, his third swipe of the game. Selzer came up and ripped a double to left to score both runners, and Purritano delivered another RBI single, this time putting Dartmouth up, 6-1.

Meanwhile, senior Michael Johnson settled in nicely after giving up that run in the first. He picked Anderson off first to end the inning, then retired the next 12 batters he faced before giving up back-to-back singles to start the sixth. Johnson worked out of that jam without a run scoring, but departed after walking Anderson and surrendering a single to Mitch Klug beginning the seventh. Junior Louis Concato came trotting in from the bullpen, got a foul pop for the first out, gave up a single to load the bases then induced an inning-ending double play to thwart the rally.

Junior Ryan Toimil and Piersma both singled to start the eighth, and Ogren lined a two-run double to right-center. A wild pitch sent him to third, and Parisi drove him in with a grounder to second for the Big Green’s final run and a 9-1 lead.

Harvard did get to Concato in the eighth with three runs, but sophomore Thomas Olson came on and retired six of the seven batters he faced to close out the win. Johnson earned his league-leading seventh victory without a defeat, allowing one run on four hits and a pair of walks with six strikeouts.

Davis (2-4) suffered the loss as he gave up four runs on five hits and four walks with five strikeouts in 6.1 innings.

Purritano, Toimil, Piersma and Ogren each had two knocks to lead the 12-hit attack, while Ogren, Selzer and Purritano each had two RBIs.

Dartmouth has one more game to play in the regular season, hosting Amherst on Tuesday afternoon at Red Rolfe Field at Biondi Park with first pitch at 3 p.m.

Notes: This was the third time Dartmouth swept the four-game series from the Crimson since divisional play began in 1993, accomplishing the feat in 1995 and 2011 as well ... freshman shortstop Trent Goodrich was a late scratch from the lineup but is expected to play next week. Parisi moved over from second to play short while Ogren made the second and third starts of his career ... Piersma was making his fifth start of the year, and he hit a double in each one.