None of us has ever seen anything in a debate like what happened last night during the first half-hour in St. Louis.

Forget the audience participation, at least in the early going. Forget the eye contact, the folksy responses. It was nasty, it was a train wreck. It was all about Donald Trump, trying desperately to save his campaign.

And it looks like he did. He lives to fight another day. Who would have bet 24 hours ago that he would come out on top in a “one-on-three” alley fight, as Trump put it in an aside near the end.

Trump came out of the box throwing haymakers at Hillary and everyone else in his way, including Bill Clinton, who was there in the hall, as were three of the women who have credibly accused him of attacking them. He drew the distinction between Clinton’s sordid past and his own leaked audiotape from 2005.

What choice did he have?

“It’s just words, folks, it’s just words,” he said of the audiotape. “That was locker room talk. I’m not proud of it… (But) mine are words, his was action. … Hillary Clinton attacked those same women, attacked them viciously.”

That was around 9:17. Eight minutes later, after another blast, she tried to get out from under his unrelenting attack.

“Everything he just said is absolutely false,” she said.

“Oh really?” he responded.

“It’s just awfully good that someone with the temperament of Donald Trump is not in charge of the law in our country,” she said.

“Because you’d be in jail!” he said.

At 9:28 she tried to get away from his relentless monologue on the emails.

“I’d like to get into the people,” she said.

“You’d like to get away from this,” he interrupted.

But he couldn’t keep it up. The moderators had their marching orders. Send him back to this corner, let the bell ring and hope she could regain her composure.

But he wasn’t observing any of the niceties that a town hall forum is supposed to feature. As she spoke, he didn’t bother making eye contact with the questioners. He kept roaming around the stage. He stood behind her. He turned his back on her. He prowled some more. At one point he seemed on the verge of walking off the stage. He put his hands on the back of his stool and stared straight ahead.

The second questioner hit Hillary right between the eyes on Obamacare: “Affordable care. It’s not affordable.”

She can’t defend it, nobody can. But he still doesn’t have a clear enough understanding of what the problems are. People have been telling him for weeks, maybe months, to come up with a tighter answer. It’s a giant issue. But he won’t study it.

Then she got a question from Martha Raddatz on the Wikileaks dump of John Podesta’s emails, about her statement to Goldman Sachs about the need to have a public face and a private face. Her reference gave her a chance to compare herself to Abraham Lincoln — Abraham Lincoln!

I’d rather have had her answer about her admission that she can’t identify with the struggles of the middle class. Or about her call for “open borders.” But hey, at least they brought it something.

“She lied,” he said. “Now she is blaming the lie on the late great Abraham Lincoln. Honest Abe never lied.”

At 10 p.m., Hillary blamed George W. Bush, I think for the bad economy. How predictable.

At 10:10, Martha Raddatz went all Candy Crowley and started debating Donald Trump on Syria. Even more predictable.

At 10:18, Hillary said, “Bullying is up.” Fact checker, please!

At 10:21, Trump finally mentioned Benghazi. What took so long?

I watched Trump slip the noose and thought about being with him in Sandown, N.H., at a “town hall” just 72 hours earlier. It was supposed to be a way for him to figure out how to handle himself in such a forum.

Judging by what happened last night, I think what he figured out in Sandown was that town halls are a joke, at least if you’ve endured the beating he had over the preceding 48 hours.

Good call … I think.

Listen to Howie 3-7 p.m. on WRKO AM 680.