CLEVELAND — Donald Trump Jr. on Wednesday accused former campaign manager Corey Lewandowski of being “bitter” and trying to “sabotage” Donald Trump Sr.’s presidential campaign.

The sharp words come in response to Lewandowski’s statements in the press that Paul Manafort, the man who replaced him, should resign for approving Melania Trump’s much-criticized convention speech.

At a Wall Street Journal breakfast Wednesday morning, Trump Jr. said the former campaign head was trying to settle a score — and telling reporters lies about the campaign.

” [When] I see him go on TV knocking the guy that ultimately replaced him, I get it,” Trump Jr. said of Lewandowki’s attacks on Manafort.

“I understand. I’m human. I can understand why someone’s bitter about that, but that doesn’t help. You can’t claim to be an ally and then try to sabotage the guy that you’re upset with, who was brought in to work with you, and you couldn’t do that, couldn’t play with everyone, so we had to make a decision.”

Trump Jr. accused Lewandowski of badmouthing the campaign to reporters — and making up details about private campaign strategy meetings.

“Enough’s enough,” Trump Jr. said.

The Donald’s eldest son said the campaign did what it needed to do by firing Lewandowski.

“He’s been a very good, strong advocate for us. I think he did great things initially for the campaign, but I think the campaign did have to evolve, did have to mature. … It had to have people in there who have done this before,” he said.

“I couldn’t be happier with Paul and his team.”