Punches were thrown on the race track after a coming-together between two drivers in the 500 Milhas de Kart event in Brazil.
Rodrigo Dantas had been unloaded into a tyre barrier by Tuka Rocha, and responded by pinning his rival and throwing a series of punches at Rocha, who was still wearing his helmet.
Security guards had to step in to end the fight, which saw both teams’ karts, MDG Matrix and Sambaiba Centerbus Racing, disqualified.
Felipe Massa was also driving for MDG Matrix and expressed his lament at what had transpired.
There had previously been a running battle between the teams throughout the race, which lasted just under 12 hours, and Massa said this was the catalyst for what transpired.
“From what I saw, the whole team should be disqualified,” Massa said of the previous encounters between them.
“But that did not happen, and what happened next was a war inside the track.
“For me, this is very sad and sadder still to see my team within that. It was not my decision – I was driving the (leading) kart – but I apologise to everyone for what happened, because I have never seen anything like it in my career.
“The competition is inside the track, but never in this way.”
Event organiser Felipe Giaffone said after the race: “We will take appropriate steps to banish the culprits from these unfortunate scenes.”
Rubens Barrichello’s Hero # 71 team win the event as a result of the disqualifications.
VIDEO: The incident and resulting fight