In 2009, he asked for that marriage contract to be sent to a divorce lawyer in Montreal. Two months later, Gatti was dead.
But his widow denied Thursday having much knowledge of the one-sided agreement she signed in August 2007 and flatly denied that it had prompted her to stave off divorce proceedings.
Amanda Rodrigues faced intense questioning during her second day of testimony in the bitter court battle, pitting her against Gatti's family, over the late boxer's estate.
Rodrigues said she signed the prenuptial without having fully read it and insisted she was unaware of its details while she was fighting to keep their marriage going.
She was adamant when asked whether she had ever discussed the prenuptial contract with Gatti.
"No, never," Rodrigues replied in response to a question from Gatti family lawyer Carmine Mercadante.
However, that same agreement was enough of an issue between the two that the couple went to a lawyer's office days after their 2007 wedding and, according to a firm employee, Gatti tore up a copy of the contract.
Rodrigues said she never asked the boxer to do that. She said he agreed to destroy the contract as a gesture of love for her.
However, according to another witness, Gatti apparently made sure that the agreement remained valid. The lawyer's secretary testified that she gave him a copy.
By 2009, the couple was experiencing serious marital problems and Gatti contacted his New Jersey lawyer -- asking him to send the prenuptial agreement to his Montreal divorce attorney. Rodrigues had also contacted a divorce lawyer.
The couple subsequently took two trips together. On that second vacation, in Brazil, Gatti was found dead.
The late boxer's family does not believe Brazilian authorities' conclusion that he committed suicide; a report into his 2009 death, privately funded by his former manager, indicates the death was a homicide.
Authorities in Brazil are now taking a second look at the case while the Gatti clan is fighting to keep his widow from inheriting his fortune, valued around $3.4 million.
The couple had a will drawn up about three weeks before Gatti died, naming Rodrigues as the executor of his estate. However, the Gatti family says a 2007 will that is unsigned remains valid and that the 2009 will was created under pressure from Rodrigues.
After being painted as a money-obsessed, foul-mouthed wife by Gatti's friends, Rodrigues has faced intense questioning during the hearings and has been caught in several contradictions.
She has testified that she had no idea he was a famous boxer when they first met; however, when it was pointed out that Gatti had just been scuffed up in a match that month, she changed her story about the date of their first meeting.
Rodrigues also testified that he decided to tear up the prenuptial agreement just days after returning from their 2007 wedding, but lawyer John Lynch said the event occurred months later.
The court also heard that Gatti contacted his law firm just one week after tearing up a copy of the prenuptial agreement, to ensure the original copy was still intact.
"He knew it wasn't the original, but he ripped it up," said Kathryn Appello, Lynch's secretary, who said Gatti winked at her before tearing the document in two, a sign to her that he knew it wasn't the original.
"Amanda had a smirk on her face and they left."
A week later, Appello testified that Gatti called her: "He asked if I still had the original and I said, 'Of course Arturo,'" Appello said.
Appello testified that Gatti called and asked that a copy of the contract be sent to a Montreal lawyer he'd consulted for a divorce from Rodrigues in May 2009.
Rodrigues was adamant on another thing: She said she never saw any document being destroyed. She said that when they went to the law firm, Appello told her the prenuptial contract was in the mail. Rodrigues said it never arrived and she simply assumed it was lost.
Several times Thursday, Rodrigues said the document didn't matter to her.
The court also heard that just before the couple got engaged in April 2007, Gatti had a will drafted that left everything to his mother and his daughter Sofia.
Rodrigues dismissed that notion: "I don't believe that will ever existed." However, under questioning, she also appeared to acknowledge that her name did not appear in that document.
Later, Rodrigues was questioned on her personality and attitude, quizzed about altercations with her husband that involved police. One drunken altercation involving police occurred on vacation in Hawaii.
Rodrigues was drunk and had been fighting with her husband.
A police report described the 2008 incident as an "abuse-type case" where Rodrigues was unstable, unable to stand on her own two feet and smelling of liquor before becoming belligerent toward an officer.
The report said Rodrigues screamed at the officer, unleashing a torrent of profane epithets against him.
She was also asked about an incident outside a Montreal restaurant in 2009. A Montreal police complaint, filed by Gatti, says she keyed his truck while the boxer and their infant son sought refuge inside.
The incident occurred one month before Gatti's death.
Asked by Mercadante if she was prone to anger and aggression, Rodrigues replied that she didn't think she was worse than anyone else.
She said she fought with her husband about once a week -- something she considered normal for married couples -- but that she was calm and patient when she was first married.
But she said she grew tired of having the same arguments with him over his drinking and had lost patience over the spring of 2009 in what she described as "the hardest time of my marriage."
"I'm not proud of it, I'm embarrassed to say that. I'm embarrassed how I lost my temper," Rodrigues said, adding that she felt bad that her infant son Arturo Jr. was witness to the arguing.
"Junior saw a lot of things I'm not proud of."
Rodrigues returns to the stand on Friday.