HANOVER, N.H. — Seniors Sam Bean and Jeff Onstott each homered in the first game on Senior Day, and Dartmouth scored three times in both the seventh and eighth innings — all on 0-2 pitches — in the nightcap to sweep a doubleheader from Harvard on Saturday afternoon at Red Rolfe Field at Biondi Park by final scores of 4-1 and 6-0. The two victories, coupled with Yale’s loss in the first game of a doubleheader at Brown, not only thrilled the crowd of 923, but also clinched first place in the Ivy League’s Rolfe Division, the fourth consecutive crown for the Big Green.

Dartmouth (26-10, 12-6 Ivy) extended its home winning streak to a nation’s best 24 games while keeping its hopes of hosting the Ivy Championship Series next weekend. The Big Green must catch the Gehrig Division champion, Princeton (19-20, 13-5 Ivy), for the best record in league play. Should the two teams tie for the best league mark, Dartmouth would host by virtue of defeating the Tigers in both games the two played back on April 10. Princeton plays a doubleheader at Cornell tomorrow, while the Big Green travel to Cambridge to try its luck again with Harvard (9-34, 5-13 Ivy).

After Harvard hurler Eric Eadington retired the first seven batters of the opening game, Dartmouth was able to scratch a run across the plate in the third. Junior David Turnbull dropped a single into center with one out, and junior Jake Carlson walked to put runners on first and second. A balk moved them both up a base before junior Joe Sclafani grounded out to third as Turnbull scampered home for a 1-0 lead.

Sclafani blasted a two-out triple in the fifth — his eighth of the season, breaking the Big Green record set in 1938 — before Bean sent a 2-2 pitch over the scoreboard in right-center for his first career home run and a 3-0 advantage.

Sophomore southpaw Kyle Hunter was in command on the mound for Dartmouth, meanwhile, facing just one batter over the minimum through the first five innings. In the sixth, however, he ran into a bit of trouble when Danny Moskovits stroked a lead-off double and Jack Colton singled him to third. Dillon O’Neill provided what turned out to be the only Crimson RBI of the day with a grounder to the hole at short. Harvard did manage one more hit in the frame, a two-out swinging bunt to third, but could not pull any closer as Hunter got pinch-hitter Taylor Helgren to hit a pop into foul territory down the right-field line on which Onstott made a sliding catch to end the threat.

Onstott got that run back in the bottom half, hitting his second home run of the season to the opposite field in right. Hunter only issued his lone walk of the game in the seventh before retiring the final two outs on fly balls to right.

Hunter (5-2) went the distance in the seven-inning contest, allowing just the one run on five hits and one walk while striking out six. Taking the loss was Eadington (0-7) who also threw a complete game, matching Hunter in hits and walks allowed and punchouts. But the two homers were the difference in the game.

Game two was a terrific pitchers’ duel through six innings. Both Dartmouth freshman Mitch Horacek and Harvard senior Max Perlman threw less than 70 pitches over the first six stanzas in keeping the other side off the board. The Crimson threatened in the second when Marcus Way reached on an error, took second when Samuel Franklin was hit by a pitch and advanced to third on a passed ball. Horacek then got a grounder to third baseman Jeff Keller, who held Way at third while getting the out at first. When a wild pitch scooted away from catcher Chris O’Dowd, Way tried to score, only to have O’Dowd scramble to get the ball and throw a strike to Horacek covering the plate. The rookie southpaw then got a comebacker to end the inning.

The Big Green managed just three base runners in those six innings before finally breaking through in the seventh. Both O’Dowd and senior Jason Brooks singled to get things started, and Onstott moved them along with a sacrifice bunt. Harvard elected to intentionally walk sophomore Ennis Coble — who began the weekend leading the Ivy League in RBIs — to face the right-handed rookie Keller. Perlman got two quick strikes with sliders, but went to the well once too often as Keller poked a ball through the left side. O’Dowd and Brooks scored, and when Coble went to third on the throw toward the plate, the third baseman cut the throw and tried to get the out at third. His off-balance throw sailed high, however, allowing Coble to come around as well for a 3-0 Big Green lead.

In the eighth, Brooks delivered an 0-2 single through the right side of the infield to score Sclafani, who had walked, and Coble looped a two-run single to right-center on an 0-2 pitch as well.

Freshman Mike Dodakian (3-1) picked up the win on the mound having relieved Horacek with one out in the top of the seventh. The right-hander tossed 1.2 scoreless innings before senior Ryan Smith shut the door in the ninth with a little help from his defense. Colton hit a lead-off single and Jeff Reynolds doubled him to third with one gone. But when Way hit a sinking liner to left-center, Bean made a nice running catch and threw behind Reynolds who thought the ball would drop. The throw beat Reynolds back to the bag before Colton could cross the plate, keeping the shutout intact.

The doubleheader between these two teams begins at 1 p.m. tomorrow at O’Donnell Field.

The Class of 2011, the winningest class in Dartmouth baseball history with a 105-64 record thus far.