Despite clams that the repeated calls to Sebastian Vettel to ease off in the closing stages of the race were not based on genuine concerns, team boss Christian Horner admits that the situation was for real and the German's win was balanced on a knife edge.

Time and time again Vettel, and his teammate Mark Webber were warned that wear to their right-front tyres was causing concern, the messages increasing in urgency. At one stage Vettel being told that he would not know until it was too late.

On the Red Bull prat-perch feet were shaking, brows furrowed, fists clenched and lips bitten. At one stage, like a naught schoolboy who had been caught out, Vettel attempted to calm the situation; "I'm looking after my tyres," he said somewhat sheepishly.

Post race it was claimed that the situation wasn't as dire as the messages suggested, that the team merely wanted the German to ease off and not do anything silly, not so insists Horner.

"It was quite a long final stint, it was 22 or 23 laps, which we knew would be right on the limit," the Red Bull boss admitted. "So it was about making sure we did not punish the tyres too much and making sure we had enough to get to the finish.

"That is why I said to Rocky - Guillaume Rocquelin, Vettel's race engineer; 'make sure you are all over Sebastian because we don't need any fastest laps and then have Mark trying respond one lap from the end'. Knowing how much we had stretched the tyres was a concern, other teams must have had the same issue, and then every time the TV was bringing up a slow-motion replay of bits of an inner edge flying off. I decided I could not look at those any more from about half distance, I focused on the data instead."

Vettel got the car to the flag to take his third successive win and the championship lead, though he couldn't resist setting the fastest sector time in S3 on the final lap of the race.