(Adds quotes, detail, Sutil penalty)
By Alan Baldwin
MONZA, Italy, Sept 7 (Reuters) - Lewis Hamilton said he had driven like an idiot after his bid for a fifth successive pole position fizzled out with his worst qualifying performance in years at the Italian Grand Prix on Saturday.
The 2008 world champion will line up in 12th place on the Monza grid for Mercedes, the lowest he has qualified since 2010 - not including last year's Spanish Grand Prix where a penalty took him from first to last.
"I just drove like an idiot. That's the worst I've driven for a long, long time. I'm sorry to the team," he told reporters.
"I just didn't drive well. There's not really much more to say. I was quick in Q1 (the first phase) and then I don't know. I'll do whatever I can from where I am but it's going to be tough," added the Briton.
Mercedes team principal Ross Brawn told reporters Hamilton was being overly hard on himself, explaining that the driver had not realised the car had a damaged floor after hitting a kerb earlier.
"Lewis was looking OK and unfortunately caught a kerb and damaged the car underneath, and broke the floor," Brawn explained. "We didn't realise the consequences of that until a bit later in the session. It was not repairable.
"Lewis is often his own hardest critic. It's quite endearing that he's willing to make that sort of statement," said the Briton.
Hamilton said being told the car had a broken floor made little difference to his earlier assessment.
"In the heat of the moment tensions are high and I still feel like I didn't do a spectacular job today," he said.
"I did have damage to the car. The engineers said we'd lost quite a lot of downforce, which would explain the lack of pace...but again that's due to the mistake that I made earlier in the session.
"I think someone said it's 67 races since I've not qualified in Q3 so I guess I can be a little bit easy on myself...but I just want to achieve the best for the team. Sometimes when you have those moments you just feel like you've let people down."
Hamilton, last year's winner with McLaren from pole at Monza, was also held up by Force India's Adrian Sutil who was handed a three place penalty for Sunday's race.
Brawn blamed the team more than the German driver for the incident.
"From what I understand, the team didn't advise Adrian that Lewis was coming up behind until he was on top of him," said the principal. "It doesn't sound to me like Adrian was particularly at fault."
The stewards ruled that the impeding was not intentional but said it was the driver's responsibility to be aware of the approaching car. (Reporting by Alan Baldwin, editing by John Mehaffey)