German driver Sebastian Vettel of Aston Martin started the Formula One season opener Bahrain Grand Prix from the back of the grid after a five-place grid penalty, ruling body FIA said on Sunday.
The federation said Vettel failed to respect double yellow flags during Q1 in a qualifying session on Saturday when Haas driver Nikita Mazepin had a spin at Turn 1, reported DPA.
As a result, the four-time world champion Vettel dropped from 18th to 20th on the grid on his Aston Martin debut after six years at Ferrari.
"Vettel did not abandon his lap. He explained to the stewards that he saw the smoke ahead of him, but was unsure if it was a lock-up or a stopped car until he was quite close to the car and the smoke was lifting," a statement said.
Max Verstappen of Red Bull started in pole position, while seven-time world champion Lewis Hamilton of Mercedes is second and his team-mate Valtteri Bottas third.
Lewis Hamilton won the F1 title last year while Vettel finished at 13 with just one podium finish.
Vettel had won his four F1 championship titles between 2010 and 2013.