Norbert Haug has sought to dismiss suggestions the battle for the 2008 Formula 1 World Championship has now boiled down to just a two-horse race between Lewis Hamilton and Felipe Massa.

Entering the final four races of the campaign, McLaren-Mercedes' Hamilton leads Ferrari rival Felipe Massa by the scant margin of just a single point in the drivers' standings, with the duo's next-nearest threat - BMW-Sauber's ever-consistent challenger Robert Kubica - some 13 markers further in arrears.

However, with 40 points still to play for between now and season's end, and both Hamilton and Massa having committed a number errors and been on the receiving end of some appalling ill-fortune over the course of the year, Kubica, Massa's defending F1 World Champion team-mate Kimi Raikkonen, the second BMW of Nick Heidfeld and the sister McLaren of Heikki Kovalainen all remain mathematically in play.

As long as they retain a theoretical chance of claiming glory, Mercedes-Benz Motorsport Vice-President Haug underlines - and ahead of an outing as unpredictable as the inaugural Singapore Grand Prix night race this weekend looks likely to be - it would be foolish to write any of them out of contention.

"No, I don't think so," the German responded, when asked whether he believed the title scrap is now an exclusively Hamilton-Massa affair. "As long as the mathematical chances exist, they exist. I think everybody learned their lesson last year, not least us.

"There are more than two guys involved, which is good for the sport. We should have some more points, but it is what it is. I think it is a thrilling season. We have had great races so far - very, very exceptional with rain - a new track in Valencia and now this particular track, a night race.

"I think it is going to be remembered as a remarkable season, whatever happens. The championship starts right here, because it is very close together between the top guys."