You Tube star Jake Paul, who has an ongoing feud with Conor McGregor, was furious after his fighter lost the bout in Madison Square Garden.
Paul, who has over 20 million online subscribers, went on a rant in the aftermath of the fight, claiming his fighter did enough to win or at least avoid a loss in the biggest fight in the history of women's boxing.
He claimed Katie's manager said to him in the corner after the fight "that's a draw", and promoter Eddie Hearn told him the same.
He added: "I come back to the locker room, I'm chilling in the back locker room, the girl who sang the Irish national anthem comes up to me, is like, 'Hey, can I have a picture? Amanda won that fight.'
"And she sang the national anthem for Ireland, so screw my opinion, those are three stories right there that everyone says it's a draw or that Amanda won the fight."
But beautiful Louth woman Cathy Maguire, who proudly sang Amhrán na bhFiann before the big fight, was amused at his account.
"His mum and I were bantering in the hallway and she brought me in to the changing room to meet Amanda. Katie had already left," Cathy tells the
"I met him in the dressing room where I was complementing Amanda on a fantastic performance. He interpreted our interaction to fit his own narrative for the press conference and that is to be expected.
"My words to him were…'they were both winners tonight..there were no losers. What a fantastic show from both women'."
She adds: "This is showbusiness and he has built his career on being controversial and creating havoc. The night belonged to Katie and Amanda and he was a small part of the picture that night. Though I was flattered that he referred to me as a 'girl' given that I'm forty.
"Katie's team are used to the shenanigans and take these comments with a pinch of salt."
Paul has had an ongoing war of words with McGregor, with the Dubliner sneering after Katie's fight: "Who the f**k is this jackass in the pink Jimmy Saville glasses?"
Paul, who has won five out of five fights in his career, has challenged the UFC star to a bout.
Cathy, who hails from Dundalk, was chosen by Katie to sing the national anthem before her fight having been spotted singing by the fighter's team at an event in St Patrick's Cathedral in New York, when her amazing version of 'Our Lady of Knock' which racked up millions of hits online.
She is the go-to singer for large Irish-related functions in the Big Apple and has performed for and met the likes of President Joe Biden and US House of Representatives speaker Nancy Pelosi.
Cathy also sang at the funeral Mass for Sinn Féin's Martin McGuiness and is a staunch supporter and advocate for the party in the USA.
"In the 20 years I have been in America, I have never witnessed an atmosphere like Madison Square Garden that night," she tells us.
"When I walked into the stadium to sing the anthem, it took my breath away. I can only imagine what Katie felt as she walked out there. It was a humbling experience to be invited to carry the spirit of the Irish people on an iconic, historic night in New York City.
"There was a phenomenal energy and the Irish fans sang and cheered so loud that I could hardly hear what I was singing. In a week where the Supreme Court seem to be walking back the rights of women, it was all the more poignant to be part of such a spectacular event with all-female colour guard, all-female performers, and two incredible female athletes."
She adds: "On a personal note, there are times as a singer in the quieter moments of your career where you wonder why God gave you this gift. I found the answer to that question that night when twenty thousand fans were singing with me in support of the greatest athlete Ireland has ever produced."
Cathy still can't believe the spine-tingling reaction to her singing our anthem in NYC.
"I've learned over the years that the Irish crowd will push the speed of the anthem due to pure excitement, so in Madison Square Garden I purposely kept it as slow as I could and the result was an incredibly heartfelt wave of singing from the crowd where you could hear every word," she says.
Although hailing from Dundalk, Cathy now lives between Nashville and New York. She has been singing and doing TV since childhood, and has been on The Late Late Show three times. She first visited Nashville at the age of 20.
"I got a deal three days after arriving with Johnny Cash's producer Cowboy Jack Clement but didn't act on it for years as I didn't have the confidence," she recalls. "I had anxiety and thought I couldn't possibly be able to deliver to people of that standing in the music business.
"Despite having record deals and the world's biggest producers offering to work with me, I just didn't have the confidence or the know-how at the time to grab it...It wasn't until I got older and came to New York that I really began to realise that I was as talented as the next and deserved a place on the American stage."
As well as being involved in entertainment she is also a successful businesswoman, running and owning a thriving real estate company, which has a team of 38 people across four states.
There is talk of a rematch between Katie and Amanda in Dublin's Croke Park in October and Cathy is up for singing there too.
"It would be an honour to perform the anthem in Ireland for Katie," says Cathy.