However he denied the incident was motivated by Mr Jones’ sexuality or political beliefs – claiming instead that he did not know who his victim was, and that the columnist had spilled his drink without apologising.
But police found an amount of far-right paraphernalia at his home.
The left-wing activist told the court he has been the subject of an "unrelenting" campaign of abuse by far-right sympathisers, including daily death threats.
Mr Jones said: "I'm an unapologetic socialist, I'm an anti-racist, I'm an anti-fascist and I've consistently used my profile to advocate left-wing causes."
The victim suffered cuts and swelling to his back and head, and bruises all down his body in the assault during his birthday night out on 17 August.
The court heard Jones published his first book, Chavs: The Demonisation Of The Working Class, in 2011 and landed a job as a columnist with The Independent the following year.
He moved to The Guardian in 2014 and frequently appears on radio and television on programmes including Newsnight, Question Time and Good Morning Britain.
Mr Jones has almost one million Twitter followers, 125,000 followers on Instagram and 350,000 followers on Facebook.
"What I use these platforms for is to advocate left-wing ideas and a passion and unwavering commitment to opposing racism, fascism, Islamophobia and homophobia," he said.
He added: "I frequently post on LGBTQ rights - I felt a responsibility because The Guardian didn't have any other LGBTQ columnists, I even have the Pride flag on my Twitter bio.
"Almost every single day I am the subject of an unrelenting campaign [of abuse] by far-right sympathisers."
He said he received death threats on a daily basis, adding: "It's the combination of being left-wing, gay, anti-fascist - that's everything the far-right hate.
"They've come to see me as this hate figure in their ranks."
Mr Jones said he was regularly targeted online by supporters of English Defence League founder Tommy Robinson and right-wing movement the Democratic Football Lads Alliance.
Last year, The Guardian hired a security team and commissioned a report because of the rising threats against Mr Jones online.
When asked about the claim that he had spilled Healy's drink, Mr Jones said: "That absolutely did not happen."
Following Healy's arrest, a search of his home revealed a photograph of him performing a Nazi salute.
The court heard that the photo showed Healy as a teenager but had been printed out in 2015.
Healy, a Chelsea fan, also had a football hooligan flag adorned with SS symbols and a collection of pin badges linked to white supremacist groups.
One of the items bore the name of the Combat 18 neo-Nazi group, whose stated aims include "execute all queers", the court heard.
A birthday card, featuring a St George's flag, a skull and crossbones and the words "You have been nominated and dealt with by the Chelsea Headhunters", in reference to another hooligan firm, was also recovered.
In his evidence, Healy denied holding extreme right-wing views and said the items found at his home were mementos from his time in the Chelsea Youth Firm when he was younger.
"I'm a hoarder. I never throw anything away, I just had them all that time tucked away in the back of a drawer."
He said the flag and pin badges were part of a wider collection of Chelsea FC memorabilia that the police had not seized and he was not aware of their connection to the far right.
He said: "Bearing in mind they came into my possession in 1998, there was no internet back then - the information now is easily available. As far as I knew, they were connected to football and football violence."
The court heard that Healy has a string of convictions for football violence and is currently subject to a football banning order for encroaching on a pitch.
Asked if he held homophobic or racist views, he replied: "No, it's 2020."
Healy said that, in the photograph in which he is allegedly performing a Nazi salute, his arm is held out to the right to show off his Chelsea Youth Firm tattoo.
"I've looked up the Nazi salute online, I've never seen a picture where their arm is out to the side - it's always out in front," he said.
He added: "I've got a cigarette in my hand."
Healy, from Portsmouth, is due to be sentenced on February 11 along with Charlie Ambrose, 30, from Brighton, and Liam Tracey, 34, from Camden, who have previously pleaded guilty to affray over the incident.
Ambrose and Tracey previously both denied a charge of ABH and the charge was left to lie on file, with prosecutors accepting their actions were not motivated by homophobia.
Additional reporting by Press Association