Former Formula 1 driver Felipe Massa has spoken of his dismay at the sight of two competitors - one of them from his own race team - brawling on the track at the end of the 500 Milhas de Kart event in Brazil.
Following repeated contact, former World Series by Nissan and A1 Grand Prix racer Tuka Rocha punted rival driver Rodrigo Dantas off the track. Dantas was driving a second entry in the race for Massa's own team.
Once the two cars came to rest against the tyre wall, the two drivers jumped out and started to exchange blows.
Dantas managed to pin Rocha to the ground. Their skirmish continued just inches away from karts which were still racing to the finish.
Dantas continued to repeatedly punch the other driver's helmet. He then appeared to be attempting to throttle his opponent as he lay on the ground.
Security staff and race marshals raced to separate the two drivers. The entire incident was captured by live television coverage which was subsequently posted to YouTube:
All of the karts of the two teams involved - MDG Matrix and Sambaiba Centerbus Racing - were subsequently disqualified from the results.
“For me, this is very sad and sadder still to see my team within that," said Massa, who was driving the team's lead kart at the time of the fight.
"I apologise to everyone for what happened today," he continued. "I have never seen anything like it in my career. The competition is inside the track, but never in this way."
It's a particularly embarrassing incident for Massa. Not only was his team involved, but he was also appointed the new head of the FIA's CIK/International Karting Commission last week.