The former wrestling superstar was in the middle of giving his acceptance speech at the Barclays Centre, Brooklyn, when a young fan came charging from out of the crowd, slid into the ring and jumped on Hart.
The 61-year-old was being inducted for the second time and though live coverage cut out, footage has been released showing the fan approach Hart, before a large security team - joined by mixed martial artist Travis Browne - rushes to the ex-pro's aid.
Browne is believed to have landed several blows on the fan before he was dragged out of the ring and has been hailed on social media for his quick reactions.
One person Tweeted: "If there are 10,000 people at Barclays right now, there are 9,999 you want punching you before Travis Browne."
While a second added: "Travis Browne earning a spot in the 2019 Royal Rumble."
According to reports, Hart was able to get back into the ring and finish his speech.
The fan slid into the ring and tackled the 61-year-old Hart to the ground. Credit: Facebook/Bret Hart
A spokesperson for the New York City Police Department said the 26-year-old fan is understood to have punched Hart at least once and is being held in custody while charges are filed against him.
WWE issued a statement which said: "An over-exuberant fan surpassed our security at ringside and made his way briefly into the ring.
"The individual has been turned over to the proper authorities."
The Hitman had been inducted into the Hall of Fame as one part of 'The Hart Foundation', the tag team duo he competed in alongside his late friend, Jim 'The Anvil' Neidhart, who passed away last year.
Speaking about the honour ahead of last night, the proud Canadain tweeted: "On March 1985 in Brantford, Ontario, Jim 'The Anvil' Neidhart and I officially became the Hart Foundation. On April 6, 2019, we take our place in the WWE Hall of Fame. I wish Jim was still with us to celebrate this moment, but I know he'll be on stage with me in spirit."
Neidhart's daughter Natalya accompanied Hart in the ring and was also pulled down to the floor during the attack.
Hart is one of only four wrestlers - along with Shawn Michaels, Ric Flair and Booker T - to become a two-time WWE Hall of Famer, after he was previously inducted in 2006.
The shocking incident occurred the night before Wrestlemania 35.
Featured Image Credit: Facebook/Hitman Hart/WWE