Lewis Hamilton heads for this week's European Grand Prix in Valencia believing he now has an outside chance of retaining his world championship.

He trails rival British driver Jenson Button by the daunting margin of 51 points, and can only score another 70 points before the season ends in November.

Yet Hamilton was boosted by a stunning victory last time out in Hungary, and in a special pep talk to his McLaren team at their Surrey headquarters he insisted his title defence was still alive. He said: "It's not impossible. The pressure is still on. You can say it is unlikely, but we've got to keep pushing. Not getting ahead of ourselves, but if we win every race for the rest of the year we can get 89 points."

That is just nine points fewer than Hamilton required to take a maiden championship in only his second season in Formula One.

Crucially, after an appalling start to the 2009 campaign in which he was accused of cheating and had to contend with one of the worst McLarens ever produced, the 24year-old believes he has a car that is fast enough to be a consistent front runner.

Spurred by watching Hamilton suffer the humiliation of being lapped by Button's superior Brawn GP, McLaren engineers worked around the clock to produce a raft of modifications for last month's German Grand Prix and the subsequent race in Hungary.

Their efforts transformed the car so enabling Hamilton to score a dominant victory in Budapest over Ferrari ace Kimi Raikkonen and Red Bull's Mark Webber, who had started ahead of him on the grid.

Hamilton said: "I was absolutely gobsmacked when I got round the first corner and I was easily able to keep up with Mark. The car was such a dream to drive. Honestly, it was incredible."

When Hamilton eventually took the chequered flag he let out a scream of delight over his car-to-pits radio, and he revealed he felt just as elated as when he clinched last year's title in that dramatic final duel with Felipe Massa in Sao Paulo.

He said: "In my heart all the emotions and all the adrenaline just exploded. It was like revisiting Brazil for me. It was very emotional."

Hamilton told his assembled team: "I've been here since I was 13 and I love you guys. You always inspire me to push harder. I know that if we continue to push, and work, and believe, we can win more races."