Heading into the Formula 1 Japanese Grand Prix this upcoming Sunday, the world championship has been blown wide-open. Or has it?

Following last week’s Singapore Grand Prix, Sebastian Vettel has emerged as the most compelling challenger for Lewis Hamilton’s defending crown despite technically being in third place for the World Championship. Hamilton remains at the top of the pile with 41 points separating him from his closest rival, Nico Rosberg, and a further 8 point gap with Vettel. Yet fresh from the Ferrari driver’s most dominant win of the season at Singapore, Vettel and Ferrari are hoping to show that they are not pretenders in their bid for the 2015 Driver’s Championship with six races remaining and 150 points on offer.

“Maybe we can make the impossible possible,” says Vettel during his Singapore post-race celebrations. “We still have a small chance and will go for it.”

However, incumbent 2014 Champion Lewis Hamilton asserts in the Mercedes team’s latest press release that he “had the pace to win” and that his car has lost pace since Monza, as it may have appeared before his eventual race retirement due to an engine part failure.

“I was on the prime [tyre] keeping up easily with the guys at the front on the option,” says Hamilton.

“My pace was really good when I started to lose power. I felt like the team was working as hard as they could and these kinds of things just happen.” “It’s still a long way to go and I know I lost some points today, but I was fast and on form and I will make sure I bring that out to Suzuka to fight back!”

With the Constructors Championship surely out of reach barring several miracles, Ferrari’s only chance at some first place championship glory is with Vettel and his unlikely bid. But first there is Japan.

Is Vettel’s championship surge just wishful thinking by F1 fanatics and commentators coveting some excitement at the close of the season, or can Ferrari genuinely mount the greatest comeback in F1 since Ferrari’s last World Championship in 2008 with Kimi Raikkonen – also known as, the ‘Other’ Ferrari driver.

Does the reigning world champion seem worried?

According to Christian Horner the Japanese GP will highlight whether his former driver genuinely has a shot at this year’s title.

“I think it is a long shot and I think it is very easy to get carried away in the moment,” the Red Bull team chief said. “What has been difficult to understand is the fact Mercedes have struggled to be competitive… If that carries through then Ferrari have a chance.”

Sky Sports F1 pundit and former driver Damon Hill agrees with Horner’s assessment of Ferrari’s chances:

“Definitely championship-wise there is still plenty of time out there and plenty of points for things to go wrong for Mercedes. We will have to see at Suzuka if this is a one-off blip or a trend that is continuing.”

In Japan, Mercedes will not be as encumbered by the choice of tyre for the race as was seemingly the case on the turbulent and slippery Singaporean street circuit held under humid night-time conditions.

In contrast, the Suzuka circuit will offer fast flowing corners which would have made the high-powered Mercedes cars the unanimous favourites if it were not for the issues arising in the previous race. Adding to the drama, Hamilton won last year’s race but Vettel has won four total Japanese GPs.

While Vettel praises his car as being effective on any type of circuit he has remained reserved on his chances for this Sunday’s race against the Mercedes drivers.

“I think in a way it was a big surprise to see Mercedes struggling, which I don’t expect to be the case here,” says Vettel.

“The nature of the track is completely different here so we’re going to have to wait. The weather could bring a lot of surprises as well so it’s going to be a tough weekend.”

When asked on his chances of making it two in a row, Vettel responds simply: “We’d hope so, but you have to remain realistic.”