Lewis Hamilton has admitted that he is not quite sure why he started so poorly at the Italian Grand Prix, having seen his lead at the top of the drivers' championship cut to just two points.

The Mercedes driver stuttered away from the start line and was quickly overtaken by five others, including teammate Nico Rosberg who claimed an impressive victory at Monza.

Hamilton recovered well to take second place, but he will now evaluate where things went wrong and has vowed to bounce back in order to keep his slender lead at the summit intact when returning to the track in Singapore later this month.

"It was the start. I knew my engineers would be worried and nervous of how the start went," he told reporters. "I don't know what happened. I will try to understand later. It's hard to overtake here. But I will live to fight another day."

Sebastian Vettel claimed third place in Italy, finishing ahead of Ferrari teammate Kimi Raikkonen and Red Bull's Daniel Ricciardo.