Red Bull remains cautious on championship chances after Suzuka

Vettel closed to within four points of leader Fernando Alonso with his triumph at Suzuka, and the strong pace of its car has left him as the main threat now to Ferrari's hopes of the crown.

But Red Bull boss Christian Horner thinks that the recent bad luck suffered by Alonso - who has retired twice on the opening lap in the last four races - is a warning that it too could face its own troubles over the remaining five grands prix.

"I think that Fernando is a very shrewd and formidable opponent and over a season luck tends to balance itself out," explained Horner. "Seb has had two DNFs through reliability.

"Fernando has been unlucky [in Spa] with [Romain] Grosjean, who seems to be a common factor with some of the incidents, and the puncture he picked up, so luck tends to balance itself out over a 20 race season.

"It will be down to what the two of them do on track now, and the relative performance of the cars over the remaining five races."

Although Horner suspects that the world title fight is boiling down to a battle between Vettel and Alonso, he is not yet ruling out challenges from Kimi Raikkonen or Lewis Hamilton.

"Never say never, especially this year," he said. "I think before the summer break Fernando had a significant lead, and since then we were second in Spa. We were unlucky in Monza but we should have scored reasonable points.

"We won in Singapore and we won here, so we have managed to eat into that gap. And hopefully we have some circuits coming up that should suit the characteristics of our package in the remaining races."

He added: "We have seen McLaren have had a really strong streak of performance and let's not underestimate them either, and we certainly don't.

"I think Ferrari has got big upgrades coming over the next couple of races, which they have mentioned. We can only control what we are doing and try and get as much performance out of our package as we possibly can - we cannot control what others do."