Lewis Hamilton said he was baffled by his struggles during the Australian Grand Prix after finishing in third position.
The Briton, visibly unhappy with the result after the race, started from pole position but was unable to stay in first place at the start, with team-mate Jenson Button passing him and leading all the way to the end.
Hamilton was around 10 seconds behind Button when the safety car was deployed 11 laps from the end, and he was then passed by Sebastian Vettel in the Red Bull.
Hamilton conceded he could not understand where his lack of pace was coming from.
"I really don't know, I just struggled out there," said Hamilton. "I got a shocking start which was really the beginning of it all.
"It was obviously a tough race, but congrats to Jenson it was great race for him. It would have been great to have had a one-two, but it just wasn't a good day for me."
The Briton described his result as pretty poor, but has vowed to re-group and fight back next weekend in Malaysia.
"It's okay. It's a pretty poor standard compared to some others."
"[I will ] just re-focus, get my head down and there's lots of races ahead. In these championships it's all about consistency so that is what I am going to focus on."