It was stank on a plane for the Toronto Raptors ... when 7-foot center Jonas Valanciunas blew a fart on the team jet and nearly killed all of his teammates.
P.J. Tucker captured the aftermath (asstermath) on video -- showing stars like Demar DeRozan, Kyle Lowry and others struggling to breathe.
But the funniest reaction is Serge Ibaka -- who looks genuinely pissed about the ass gas at 30,000 feet.
P.J. says the fart was so bad the team needs to burn the seat.
Still better than United ...