HANOVER, N.H. — Junior Kyle Hendricks tossed a four-hitter in the first game of a doubleheader, and Dartmouth rallied from a 6-1 deficit in game two to win both ends of a doubleheader at Harvard’s O’Donnell Field on Sunday afternoon, 3-1 and 10-8. The victories completed the Big Green’s first four-game sweep of the Crimson (9-36, 5-15 Ivy) since 1995 and extended the Rolfe Division champion’s winning streak to a season-long 10 games, the longest current streak in the country.

Despite the strong finish, Dartmouth (28-10, 14-6 Ivy) could not overtake Princeton for the Ivy League’s best record as the Tigers swept a twinbill at Cornell today to finish its conference schedule with a 15-5 mark. As owners of the league’s best record, Princeton will host Dartmouth in the best-of-three Ivy Championship Series that begins next Saturday, May 7.

Some shoddy fielding in the first inning of the opening game allowed Dartmouth to take a 1-0 lead. Senior Sam Bean drew a one-out walk and went to second when Brent Suter’s pickoff attempt got away. On a wind-blown infield pop off the bat of sophomore Chris O’Dowd, the third baseman dropped the ball for one error, then threw the ball away for another error — the third of the inning — when Bean scrambled for third, allowing Bean to score.

In the second, junior David Turnbull ripped a double to the right-center gap, plating freshman Jeff Keller who had singled and making it 2-0.

Those were all the runs Hendricks (4-3) needed as he kept Harvard in check throughout the seven-inning contest. He retired the first five batters he faced (three on strikes), before Jake McGuiggan and Taylor Helgren hit two-out singles in the second. But Hendricks fanned Tyler Albright to end the threat.

Harvard managed its lone run in the third with two out when Samuel Franklin was hit by a pitch and scored all the way from first on Jeff Reynolds’ pop fly to shallow center that fell in for a single in front of the diving center fielder, Jake Carlson, for an RBI single.

Dartmouth got that run back in the fourth. Carlson drew a one-out walk, stole second with two gone and scored on Bean’s single to center.

In the fourth, the Crimson threatened again thanks to a walk, an error and a passed ball to put runners on second and third with one gone. Again Hendricks was up to the challenge, punching out Helgren before inducing Albright to hit a foul pop.

Hendricks did not let a runner advance past first in the final three frames and picked off one of the two base runners he did allow. He surrendered just the one run on four hits and two walks while whiffing nine in his fourth complete game of the season.

Suter (2-5) took the tough-luck loss, striking out 11 in his complete game, yielding three runs (two earned) on seven hits and two walks.

In the nightcap, Harvard led by as many as five runs while scoring in each of the first six innings to take an 8-4 lead into the seventh. But the first seven batters for the Big Green in that inning reached base, going station to station. Carlson led off with a single, junior Joe Sclafani walked and freshman Dustin Selzer singled to load the bases. O’Dowd then stroked an RBI single to right, leading to left-hander Will Keuper being summoned to the mound from the bullpen.

After getting two quick strikes on senior clean-up hitter Jason Brooks, however, Keuper’s next offering hit Brooks to force in a run. Senior Jeff Onstott also got hit to bring Dartmouth within a run, and sophomore Ennis Coble tied the game with a base hit. Exit Keuper (0-5) and enter Andrew Hatch, who was able to retire the next three batters, although Keller broke the deadlock with a sacrifice fly for a 9-8 Big Green lead.

Sclafani chipped in an insurance run in the eighth by blasting his fourth home run of the season into the hedges beyond the right-field fence.

Meanwhile, senior right-hander Ryan Smith (3-1) was handling the Crimson bats. While the first pitch he threw was deposited over the scoreboard in left for a two-run round-tripper by Jack Colton to give Harvard an 8-4 lead in the sixth, Smith gave up just one single after that over the final 3.2 innings to earn the win.

The Crimson got an RBI double by Reynolds in the first, a two-run two-bagger by Albright in the second and a solo shot by Sean O’Hara in the third to take a 4-0 lead. O’Dowd got the Big Green on the board in the fourth with a solo shot to left-center, his sixth of the season and first in nearly a month.

But Harvard tacked on solitary runs in the fourth and fifth to take a 6-1 lead. It could have been more as senior reliever Colin Britton came on in the fifth with runners at first and second with nobody out, and the runners promptly pulled off a double steal on his first pitch. But Britton minimized the damage by inducing two grounders to short — the second of which scored the Crimson’s sixth run — and a routine grounder to first.

The Dartmouth comeback began in earnest in the sixth when Selzer walked with one down, O’Dowd reached on catcher’s interference and Brooks walked to load the bases. Onstott found a hole in the right side for a two-run single to end the fine outing by Ben Sestanovich, who allowed just two hits in his 5.1 innings. Coble greeted reliever Daniel Berardo with a sacrifice fly to make it a 6-4 ball game.

Dartmouth has one game left on its regular-season schedule, that being at Hartford on Tuesday afternoon at 3 p.m.