Donald Trump tried to praise the heroes of 9/11 at a Buffalo rally Monday — but botched the compliment by saying cops and firefighters responded on “7-Eleven.”

After an impassioned introduction by former New York Jets coach — and current Buffalo Bills coach — Rex Ryan, the GOP front-runner fumbled his remarks while launching into a defense of New York values.

“It’s very close to my heart,” Trump told the huge rally.

“I watched our police and our firemen down on 7-Eleven, down at the World Trade Center, right after it came down, and I saw the greatest people I’ve ever seen in action.”

The crowd seemed to let Trump slide on his convenience-store reference, but it wasn’t the only gaffe.

He later praised Ryan for winning AFC championships while with the Jets — who won no such titles during his tenure.

“He’s a great, great football coach,” Trump said. “You know he won the championships in New York, AFC, I think, twice.”

Ryan — who hours earlier played coy by saying he wasn’t necessarily endorsing Trump — left no doubt The Donald is his man.

“We’re all here tonight because we all support Donald Trump,” he said. “This man is one of the great businessmen, obviously, you know, that we could ever remember. There’s no question about that.”

Trump cooed over Ryan’s support, saying, “You are going to have a very, very great season this year.”

Trump is expecting a huge win in Tuesday’s New York primary and used his stump speech to taunt rival Ted Cruz for his derogatory “New York values” comment, declaring the Texas senator “hates New York.”

“No New Yorker can vote for Cruz. And no New Yorker can vote for [John] Kasich, who voted in favor of NAFTA, which has been a disaster for this state and this country,” Trump said at the First Niagara Center, where security had to eject several protesters.

Hoping to block Trump from sweeping all of New York’s 95 delegates, Kasich campaigned in Syracuse and Schenectady on Monday, while Cruz started his day with a town hall on “Good Morning America” before dashing off to Maryland.

Earlier on Monday, The Donald met at Trump Tower with a group called the National Diversity Coalition for Trump, which defended him as fair-minded.

Public polls show Trump running away with Tuesday’s primary. An Emerson College poll Monday gave Trump 55 percent and Kasich 21 percent, with Cruz trailing at 18 percent.

Jerry Skurnik, a political consultant who has analyzed voter-turnout statistics for decades, said he anticipated 800,000 GOP voters would go to the polls, compared with 635,000 in 2008.

Meanwhile, a shake-up in the Trump campaign has put Paul Manafort and Rick Wiley in charge of upcoming primary states and pushed trusty aide Corey Lewandowski to the side, according to Politico.

The move prompted a Lewandowski ally, national field director Stuart Jolly, to submit his letter of resignation, Politico said.

Additional reporting by David K. Li