CAMBRIDGE, Mass. — The Dartmouth baseball team finished a four-game sweep of Harvard by taking both ends of a doubleheader this afternoon at O’Donnell Field, 9-0 and 5-3. The victories elevated the Big Green (17-19, 11-9 Ivy) into a tie for first in the Ivy League’s Rolfe Division standings with Yale, setting up a one-game playoff with the Bulldogs to be played at Dartmouth’s Red Rolfe Field at Biondi Park this weekend. The date has yet to be determined. The Crimson conclude their season with an overall record of 11-28 and 5-15 in conference play.

“I am so proud of our guys,” head coach Bob Whalen said after the twinbill. “It’s tough to beat a team four times, especially with what we had on the line to try and force a playoff. We talked during last week about this series being four one-game playoffs for us, and these guys came through each and every time. And it wasn’t easy because even though Harvard had been eliminated from the race, they really came to play.”

Freshman right-hander Mike Concato (2-2) was brilliant in the opener, tossing his second straight complete-game shutout. The rookie finished off the seven-inning contest in just 82 pitches, scattering seven hits while walking one and fanning three.

“Mike was terrific today in less than ideal playing conditions,” said Whalen. “He was able to work out of some trouble early in the game, then just kept getting stronger as the game went on.”

The two teams were in the midst of a thrilling pitchers’ duel between Concato and Harvard’s Nick Gruener when the Big Green blew open the scoreless game with nine runs in the sixth — their biggest scoring inning of the season — on just four hits. Junior Matt Parisi walked to lead off the frame, and senior Jeff Keller followed with a single. The bases were loaded when sophomore Nick Ruppert was plunked, and junior Thomas Roulis drove in the first two runs with a solid single to right.

With runners on the corners, senior Dustin Selzer pulled a grounder to the third baseman, who tried to get the out at the plate, but threw wildly as everyone was safe to make it a three-run game. Sophomore Joe Purritano followed with a single off the pitcher to load the bases again, and junior Nick Lombardi walked on four straight pitches to force in the fourth run.

Another grounder to third, this time off the bat of junior Bo Patterson, resulted in a force out at third, but also brought home another run. Junior Matt MacDowell hit a tapper to first for the second out, bringing Parisi to the plate for the second time. Gruener hit Parisi with a 2-2 pitch, his last of the game, as Harvard finally turned to its bullpen and summoned Joey Novak. Keller greeted the right-hander by driving a full-count offering over the fence in left for a grand slam to put the final stamp on the outburst.

Concato needed just four pitches to retire the side in the sixth before allowing two runners to reach base in the final frame. Up to the plate stepped Mike Martin, who had hit safely in each of his three at-bats in the game, but Concato induced a simple comebacker for the final out and end the 9-0 victory.

Dartmouth had just six hits in the first game with Keller and Purritano each collecting a pair. Seven of the nine hitters in the lineup scored at least once, while Keller led the Big Green with four RBIs thanks to his grand slam.

In the second game, Dartmouth faced a 2-1 deficit entering the fifth inning when the offense kicked in again. And again it was Parisi serving as the catalyst as he stroked a one-out single to right. Keller ripped a single through the hole between short and third, but Crimson starter Matt Timoney induced a grounder to third for a force at second, but Ruppert beat the relay to first, leaving runners on the corners with two down. As he did in the first game, Roulis came through with a clutch single, knotting the score at two, and Selzer followed with an RBI single of his own to put the Big Green on top. For good measure, Purritano drove a 1-1 pitch over the center fielder’s head for a two-run double and a three-run lead.

Harvard scraped out an unearned run in the eighth against sophomore reliever Duncan Robinson, but left another potential run on third when the tall right-hander fanned Jake McGuiggan — who was 3-for-3 with a homer in the game — to end the inning. Robinson made quick work of the Crimson in the ninth with a strikeout sandwiched between a pair of grounders to finish off the Big Green victory.

Robinson entered the game to begin the fourth inning with the score tied at one as Whalen wasted no time in going to his bullpen ace. Harvard did touch him for a run in his first inning on the mound on a McGuiggan single to score Jack Colton. But Robinson allowed just two more hits over six innings while yielding two runs, only one earned, walking one and striking out five to improve to 6-2 on the season.

The Big Green had taken an early 1-0 lead in the second when Purritano came around to score after walking to lead off the stanza. But McGuiggan provided the first Crimson hit of the game to start the third by belting a 2-0 fastball for his first home run of the year, knotting the score. Harvard then loaded the bases with just one out, but junior Chris England escaped with no further damage by getting a shallow fly to center and a force out at third.

Timoney (3-5) took the loss for surrendering five runs over 4.2 innings on eight hits and two walks with three strikeouts. Three senior relievers, pitching in their final collegiate game, combined to shut Dartmouth out the rest of the way, led by Sam Dodge who fanned four in 2.1 innings.

Keller, Roulis and Lombardi all had two hits for the Big Green as eight of the starting nine had at least one of Dartmouth’s 11 knocks.

“We were able to string together big hits when we needed them to sustain big innings,” Whalen noted. “Roulis came up with the hit that opened the door each game, and the guys behind him kept it going. Keller sealed the deal in the first game with his grand slam, and I don’t know how Purritano hit that double as far as he did in game two into that wind. He really put a charge in that one.”

Dartmouth has one last tune-up before the playoff against Yale when the Big Green host Siena (16-26) on Wednesday afternoon at 3 p.m. The game will be streamed live via Big Green Insider on the Ivy League Digital Network.

Notes: Dartmouth has won seven straight games, making this the seventh straight season it has had a winning streak of at least seven games ... the Big Green earned the right to host the playoff against Yale by beating the Bulldogs three out of four in the season series ... Dartmouth has won the last nine games against Harvard and 17 of the last 18.