Lewis Hamilton confessed he does not know what led to his sluggish start to the Italian Grand Prix, despite taking the blame over team radio.

Hamilton qualified on pole for the race of Monza but was slow off the line and went into the first turn in sixth position, informing Mercedes it was his fault.

The defending world champion worked his way back to second with a one-stop strategy, though with team-mate Nico Rosberg topping the podium his lead in the drivers' standings now stands at two points.

Despite having shouldered the responsibility for his poor start, Hamilton admitted he only did so because he wanted to ease any concerns his team in the garage may have been having as a result.

He said: "To be honest, I said that to reassure my engineers who I knew would be feeling nervous. 

"I don't know what happened, l did everything as normal. I did the sequence exactly the same. I just got lots of wheelspin.

"I could see Nico pulling away and l knew from quite an early stage that winning the race would not be possible. Second was the best l could do after the start l got."

Head of Mercedes-Benz Motorsport Toto Wolff said the team will investigate the reason behind the poor start.

"Lewis came on the radio and said it was his mistake and we have to analyse it," Wolff said on BBC Radio 5.

"We want to give more responsibility to the driver and this time it went against him. But he has had many good starts and it can happen."