Donald Trump decimated his Republican presidential rivals Tuesday night with a clean sweep of five Northeastern states.

It was an easy — and early — victory for the billionaire businessman, who was the projected winner in Connecticut, Pennsylvania and Maryland just one minute ­after polls in all five states closed at 8 p.m.

By 8:26 p.m., Rhode Island and Delaware had also been called in his favor.

“I consider myself the presumptive nominee,” Trump declared in a victory speech at Trump Tower in Midtown, with New Jersey Gov. Chris Christie at his side.

“Governor [John] Kasich and Senator [Ted] Cruz should get out of the race . . . As far as I’m concerned, it’s over.”

Cruz, who has been arguing for a contested convention that might make him the nominee, finished a humiliating third in four of the five states.

Only in Pennsylvania did he best Kasich for second place.

Looking ahead, Trump insisted that he would defeat Hillary Clinton “so easily” in the November general election.

Trump exceeded poll projections and won at least 105 of the 172 delegates up for grabs.

Veteran GOP consultant Ed Rollins, who ran President Ronald Reagan’s re-election campaign, said Trump’s momentum spells “the beginning of the end.”

“People better get comfortable with Donald Trump,” Rollins said. “He’s going to be the nominee.”

Pennsylvania Republican Party Chairman Rob Gleason said Trump earned a “huge” victory with an “unbelievable” turnout.

“Pennsylvania went big for Trump. It’s remarkable. The Keystone State is Trump country,” Gleason said. “He’s doing better every day against Hillary Clinton. He could beat her.”

While 54 of Pennsylvania’s 71 GOP delegates were free agents, Trump said they had a “moral” obligation to back him, given the size of his victory.

Some observers said that Cruz’s campaign was toast after the rout Tuesday, with TheGatewayPundit.com declaring him mathematically eliminated from winning the delegate race and left with only the hope of a contested convention to keep his chances alive.

Trump has largely dominated races along the Eastern Seaboard, taking more than 50 percent of the vote last week in New York, where he picked up 89 key delegates.

He fared unusually well among women, capturing more than half of the female vote in Connecticut and Pennsylvania, according to early exit polls.

“I’ll do far more for women than Hillary Clinton will ever do,” Trump proclaimed.

Aware of his imminent loss, Cruz claimed at an Indiana rally that the media was backing Trump so Clinton could ultimately seize the presidency.

Kasich and Cruz have begun employing an unusual divide-and-conquer strategy in an effort to prevent Trump from becoming the GOP nominee.

Kasich has agreed not to campaign in Indiana for its primary next Tuesday while Cruz is bowing out of primaries in New Mexico and Oregon.

“It shows ineffectiveness, it shows a failing campaign — it’s collusion,” Trump said of the pact.