London - Sebastian Vettel fully deserved the penalty that cost him victory in Sunday's Canadian Grand Prix, 2016 Formula One world champion Nico Rosberg said on Monday.
Rosberg, who won his title with Mercedes, defended race stewards after they drew a storm of criticism from fans and former drivers.
He also criticised Ferrari's Vettel, a four-times champion, for making the mistake that led to the five second penalty and then complaining afterwards.
"Vettel was screaming 'I have dirt on my tyres, I was out of control, where do you want me to go... I was struggling to control the car, and I couldn't see Lewis (Hamilton)'," Rosberg said on his YouTube channel.
"OK great. But Lewis is there. So the rule says when you go off the track, you need to rejoin safely.
"It's very, very clear that unfortunately it was an unsafe return to the track. That is the rule... a penalty is deserved in that case," added Rosberg. "Absolutely a fully-deserved penalty."
Vettel led from pole position to chequered flag but the five seconds added on, for running wide and returning to the track in an unsafe manner, handed victory to Mercedes' Hamilton, Rosberg's former team-mate.
Vettel said the race, which had been shaping up as a thrilling battle between him and five-times world champion Hamilton, had been stolen from him and suggested the stewards were blind.
Rosberg said he had spoken to his father, 1982 world champion Keke, who felt the decision had been 60-40 in favour of a penalty.
The former Mercedes driver recognised fans wanted to see exciting racing but rules were necessary because "some of those guys are just too crazy out there."
"If you just leave it completely up to them (the drivers), it's going to be gloves off out there and at some point it gets too dangerous," he added.
Rosberg criticised Vettel for mistakes under pressure and wasting energy complaining.
"I wish I could say how awesome Sebastian is, like I did after qualifying but I can't," he said of his fellow-German.
"Instead of complaining on the radio when the decision is made, which he knows he can't influence any more anyway, he just keeps complaining and complaining rather than focusing on the driving and trying to get those five seconds out.
"So that was a weakness. He has such strong self-belief, and always thinks he is in the right and then always wants to blame other people and just loses focus in those moments and doesn't make the most of it. So that was not great to see from him."