Andrea Iannone wiped himself and Ducati team-mate Andrea Dovizioso out of a double podium finish, just metres from the end of the Argentine MotoGP.
Iannone began the race making contact with Marc Marquez at turn one and ended it with a dubious lunge inside Dovizioso to try and snatch second at the penultimate corner.
Instead, he skittled them both into the gravel and was later handed a three-place grid penalty for next weekend's Austin round, plus a penalty point.
While Iannone was out on the spot, the pair were so near to the finish that Dovizioso pushed his machine over the line in 13th.
“I'm okay. I'm just disappointed,” Iannone said. “For sure I worry for the team and my team-mate Andrea. It is a very difficult because, yes, I went down and touch Andrea. Both me and Dovizioso would have been on the podium so to finish the race in this way is unbelievable.
“I didn't brake too late. I braked in the same point, but I stayed a little bit more inside because I had Andrea on the outside... I've been in Race Direction. But for sure I will say sorry to Andrea. Fortunately, I have a good relationship with him.
“I was fast all weekend, in the dry and wet, and have a really high potential. For sure this is a disaster, but is like this.”
Ducati Corse Sporting Director Paolo Ciabatti declared: “Trying the extreme pass at the last corner is good if you're going to win the last race. I don't think in the second race, when you are second or third. That's the only regret we have.
“Andrea Iannone was riding a great race after a difficult start and I know he is the first to be upset with what happened. It would be a night when we would have been out drinking beers together and I think instead we're going to go to bed very early.”
The incident handed Valentino Rossi second place with Marquez's Honda team-mate Dani Pedrosa promoted to third. It also meant that, instead of being just one point behind new title leader Marquez, Dovizioso is 18-points behind.
Iannone meanwhile is yet to score, having also fallen during the opening round in Qatar, when Dovizioso finished second to Jorge Lorenzo.
The pair are under pressure to perform given the rumours that reigning world champion Jorge Lorenzo could join the team in 2017.