Ben Odierno, the millionaire landlord who fatally stabbed his wife at least 24 times as they argued over divorce in the couple's Upper East Side townhouse, was acquitted of her murder Tuesday.

A Manhattan jury deliberated only four hours before reaching the surprise verdict, which brought Odierno, 73, to tears of joy.

Jurors said afterward most panelists voted not guilty because they couldn't be sure if Odierno stabbed and slashed Christine, his wife of nearly three decades, in cold blood or self-defense.

"We'll never know what happened inside that kitchen," said juror Mark Flowers.

Odierno — behind bars for the last 21 months — said it didn't much matter.

"I feel like I'm back again," he said, beaming exultantly as he left the courtroom on the arm of his sister, Margot. "From heaven, to hell and back."

Christine Odierno's 86-year-old mother, Jennie Kramer, was not in the courtroom; efforts to reach her by phone were not successful.

Last night, an ebullient Odierno dined on lamb chops and celebrated with family and friends at Lusardi's on the Upper East Side, tossing out a toast-like greeting to his former jailmates: "I'm all for the boys in the Tombs!"

"I feel great," he said before leaving the restaurant in a black VW Jetta.

Odierno was cleared despite what even trial judge, Manhattan Supreme Court Justice Gregory Carro, had initially called "a very strong case."

Odierno's younger wife suffered some 40 injuries in the couple's November 2005 struggle-to-the-death as they argued in their East 84th Street townhouse over their impending divorce and the distribution of the family's $10 million in property.

The injuries included at least two dozen stabs and slices — many of them to the hands and forearms, seemingly indicating she was in a defensive position.

"Make no mistake about it," prosecutor Kerry O'Connell had said in closing arguments Friday.

"He's enraged. He's enraged that this b**ch, this frigid woman who's kicked him out of the bedroom now, for 10 years, is trying to take his wonderland away from him," she said, referring to the pair's argument over their $1 million Catskills get-away in Highmount, N.Y.

But defense lawyers put Odierno, the couple's two adult sons, and several neighbors on the stand to describe Christine, 57, as so jealous and so unstable that she was perfectly capable of accosting her husband with a knife.

The three Odierno men — Ben, and sons Stephan, 28, and Marcus, 25 — took turns nearly identically describing Christine to jurors as paranoid and prone to irrational fits of rage.

Odierno collapsed into sobs when the forewoman uttered the single "Not guilty" that set him free.

"It was a tough ride; it was a tough ride for the boys," he said of his time in custody — first cuffed to a hospital bed as his eight abdominal stabs, none life threatening, were patched, then at Bellevue for depression, and then at lower Manhattan's Tombs.