PRINCETON, N.J. — It was February 21, 2009. Barack Obama was just beginning his stint in the Oval Office. The Philadelphia Phillies were atop the baseball world. “Slumdog Millionaire” was about to win the Oscar for Best Picture.

And Dartmouth beat Princeton, 66-63, here at Jadwyn Gymnasium.

The Big Green hadn’t done that since until Saturday night when coach David McLaughlin’s squad knocked off the Tigers, 76-61, to cap a wild and crazy Ivy League weekend on the road. Considering how it started — with Dartmouth squandering an early 13-point lead to struggling Penn — before things unraveled in the second half in an 88-75 loss Friday night at the hallowed Palestra, he’ll take it.

“You don’t ever want to say a split is good,” said McLaughlin, whose 13-11 team moved back into sole possession of second place in the Ivy League thanks to Ryan Cornish’s 19 points and Brandon Mitchell-Day’s 15 to go with a solid defensive effort.

“When you don’t play your best basketball Friday and respond in a hostile environment against an extremely well-coached team, stick to what you want to do on both sides of the ball and walk away with win, I have to say it’s a successful weekend. I’m happy for the guys.”

No one was happier than Cornish, who overcame a nightmarish 4-for-18 shooting performance Friday to bounce back in big way with his parents watching.

“It means the world for them to come and watch me play and see us win,” said the Potomac, Md., native, who pulled down seven rebounds and handed out six assists while shooting 7-for-14 from the floor. “They’re not going to have many more opportunities.

“Last night (against Penn), we went up early. They came back, and we put our heads down after they got the lead. Tonight, we didn’t put our heads down. We picked it up a notch and went right back to them.”

In a twist of irony, both games were essentially decided by 15-0 runs.

Friday’s game was tied 53-53 with 13:59 left before the host Quakers took command over the next 4½ minutes to wrap up their eighth straight win over the Big Green in Philadelphia.

Saturday, after surging on top 18-2 and 21-4 in the first 10 minutes while Princeton missed 15 of its first 16 shots, the Tigers gradually began to chip away at the lead. By halftime they had drawn within 32-28. After Princeton missed a couple of attempts to draw even, Dartmouth found itself clinging to a 50-46 edge with 11:21 remaining,

Just when it appeared like déjà vu was happening all over again, suddenly the visitors had all the answers.

“I think the difference was we learned from the game (Friday),” said Mitchell-Day, who sank two free throws during Saturday’s 15-0, which included six points from Connor Amundsen and another five from Cornish. “Yesterday we got out of what we do well.

“A huge message coaching staff had was, ‘Keep being us.’ That’s what we did tonight, and it paid off.”

His coach wasn’t surprised.

“I thought we did a good job sticking to our game plan and staying aggressive offensively,” said McLaughlin, as Dartmouth finished the night shooting 28-for-59 (47.5%) while outrebounding the Tigers, 42-32, and holding the hosts to 34.3% shooting (24-for-70). “We really protected the paint and forced them into tough shots. Then we were able to rebound and get out in transition.”

The end result had the Big Green cheering loudly in the locker room, something that hadn’t happened here since Terry Dunn was at the helm some 15 years ago.

“I went in the locker room and said, ‘Guys, there’s a phrase: ‘Don’t be surprised by what’s not surprising,’ ” Revealed McLaughlin, who’ll now try to get Dartmouth ready to face first-place Yale on Friday in Hanover, followed by Brown 24 hours later. “I’m not surprised with how they played and got the message.

“We kind of lost our identity last night, and Penn had lot to do with it. But we didn’t play our best ball. I just think the guys were focused tonight and worked hard.”

Consequently, the Big Gren is on the verge of wrapping up a coveted spot in the four-team Ivy tournament for the first time since it was created in 2017. Dartmouth also hasn’t had a winning season since 1999. And there’s that absence of an NCAA tournament visit since 1959.

But first there’s more work to do.

“We’ve still got two more weeks and have to stay on the same track,” said Mitchell-Day, who came down hard on his ankle on a late layup attempt and had to leave the game. “We still have a lot to prove. We have yet to show our best basketball. I think our best basketball is yet to come.”