Lewis Hamilton believes it is a case of back to the drawing board for McLaren after their day of pain in Bahrain on Sunday.

Hamilton was deposed from the top of the championship standings by Sebastian Vettel as the reigning title-holder took his first win of the season and 21st of his Formula One career.

Two bungled pit stops contributed to Hamilton finishing eighth to now trail Red Bull's Vettel by four points, the German being the fourth different driver to win a race this year.

With McLaren team-mate Jenson Button retiring a lap from home when on course for fifth place, it proved a day to forget for the Woking-based marque.

With another gap of nearly three weeks now to the next race in Barcelona, which includes a rare, in-season three-day test at Mugello next week, Hamilton hopes answers can be found.

"I struggled for pace, with Sebastian pulling away at a second a lap, struggled with looking after the tyres. I just wasn't quick at all," said a downbeat Hamilton.

"I still think I could have got fourth or fifth, but to end up eighth after two poor pitstops is disappointing.

"The only positive is that I scored four points, but, overall, there aren't a lot of positives to take from the race.

"We have to go back to the drawing board and try and figure out where we are losing time, because we are quick in qualifying.

"However, something changes in the race, so we have to go back and work harder at the factory, and if anyone can fix it, it's us.

"I'm sure everyone's frustrated, so we have to look on the bright side and keep positive."

Martin Whitmarsh, the McLaren team principal, conceded his staff face "a lot of work ahead" to correct the issues that blighted their efforts in Bahrain.

With McLaren also usurped by Red Bull at the top of the constructors' championship, Whitmarsh said: "You have bad days and Sunday was one of them but we're a strong team, we've come back from these things before.

"We have to focus on and understand what we did wrong, how we weren't performing, because clearly we're doing something wrong.

"If you look at our pace in the race compared to Friday, we were a second slower. We're capable of doing that because we've good people, capable of recovering the situation, but there's no magic formula."

Lewis Hamilton believes it is a case of back to the drawing board for McLaren after their day of pain in Bahrain on Sunday.

Hamilton was deposed from the top of the championship standings by Sebastian Vettel as the reigning title-holder took his first win of the season and 21st of his Formula One career.

Two bungled pit stops contributed to Hamilton finishing eighth to now trail Red Bull's Vettel by four points, the German being the fourth different driver to win a race this year.

With McLaren team-mate Jenson Button retiring a lap from home when on course for fifth place, it proved a day to forget for the Woking-based marque.

With another gap of nearly three weeks now to the next race in Barcelona, which includes a rare, in-season three-day test at Mugello next week, Hamilton hopes answers can be found.

"I struggled for pace, with Sebastian pulling away at a second a lap, struggled with looking after the tyres. I just wasn't quick at all," said a downbeat Hamilton.

"I still think I could have got fourth or fifth, but to end up eighth after two poor pitstops is disappointing.

"The only positive is that I scored four points, but, overall, there aren't a lot of positives to take from the race.

"We have to go back to the drawing board and try and figure out where we are losing time, because we are quick in qualifying.

"However, something changes in the race, so we have to go back and work harder at the factory, and if anyone can fix it, it's us.

"I'm sure everyone's frustrated, so we have to look on the bright side and keep positive."

Martin Whitmarsh, the McLaren team principal, conceded his staff face "a lot of work ahead" to correct the issues that blighted their efforts in Bahrain.

With McLaren also usurped by Red Bull at the top of the constructors' championship, Whitmarsh said: "You have bad days and Sunday was one of them but we're a strong team, we've come back from these things before.

"We have to focus on and understand what we did wrong, how we weren't performing, because clearly we're doing something wrong.

"If you look at our pace in the race compared to Friday, we were a second slower. We're capable of doing that because we've good people, capable of recovering the situation, but there's no magic formula."