Ex-Formula One driver Felipe Massa has apologised after one of his teammates attempted to strangle his rival on the track at the 500 Milhas de Kart event in Brazil.
Rodrigo Dantas, who was driving the second kart for Massa's team, was a lap down and was holding up A1 Grand Prix racer Tuka Rocha.
After repeated contact, Rocha eventually punted Dantas to a standstill against the tyre wall, who immediately leapt from his kart ready to fight.
Read more:
Blastacars drift karts racing into the future
Motorsport: Horror speedway crash at Western Springs
Motorsport: Tony Stewart walks out of Auckland speedway meeting
Dantas pinned Rocha to the ground and repeatedly punched his helmet in retaliation before the two were wrestled apart by security guards and karts of the two teams.