Sebastian Vettel displayed all the guts and determination of a world champion to haul himself back into the Formula One title race with a Singapore victory that sets up a mouth-watering finale to the season.

Vettel kept his focus to win a "killer" race that ran for a full two hours on a balmy Sunday night, enabling the German to cut championship leader Fernando Alonso's advantage to 29 points with six rounds remaining as he seeks a hat-trick of crowns.

To say the title showdown has come down to a duel between Vettel's Red Bull and Alonso's Ferrari could be premature given the topsy-turvy nature of this season but while both men have bemoaned a lack of pace, they make up for it in consistency.

Alonso has spent all season claiming his car is not competitive, yet he has forged ahead by picking up big points from average positions on the grid, a feat he repeated in Singapore by finishing third after starting fifth.

"On track, we manage to make the most of what we have, making few or no mistakes, thanks to great work from the team," Alonso told reporters after chasing home Vettel and McLaren's Jenson Button.

"For that alone we deserve to be where we are in the classification. Today, we pulled out an advantage over three of our four main competitors, which is positive."

Vettel cut a forlorn figure after an erratic race in Monza two weeks ago ended prematurely with an alternator failure, leaving many observers to doubt whether the German had the desire or the vehicle to mount a serious title challenge.

His demeanor had changed by Sunday after a polished drive backed up his domination in practice as both he and Alonso benefited from another failure for Lewis Hamilton, who has offset three wins with three retirements in the last eight races.

All season long, McLaren's rivals have claimed the British car was the most competitive yet Hamilton's challenge took a body blow on Sunday when he surrendered the lead on the 23rd lap with a gearbox failure and is now 52 points behind Alonso.

SUZUKA NEXT

"A tremendous result for Sebastian and the team to win in Singapore. It's a timely win for both championships," Red Bull team principal Christian Horner said.

"It was unfortunate for Lewis to retire from the lead, we know how that feels and it's never a good feeling.

"Nonetheless, Sebastian had tremendous pace all weekend and it's a shame in some respects, as I'm sure they'd have had a great race over the remainder of the grand prix."

Kimi Raikkonen also lost ground in Singapore as his Lotus proved unresponsive on the tight street circuit with his sixth-place finish dropping him 45 points off the pace as he still searches for a first victory in his comeback season.

The teams now head to Suzuka for the Japanese Grand Prix on October 7 and while the circuit is a sweeping tribute to near-perfect track design, the title contenders have only one thing on their minds - to finish in the points.

"(The championship situation) looks better than before," Vettel said after collecting his 23rd career victory.

"Fernando finished third and it's 10 points better than before. There are a lot of races left, and it's difficult to predict what is going to happen but we have to make sure we finish the races.

"The pace is there and even if we are not quick enough to win - we have to make sure we do that. It is a tough championship so far but we are still in it."

Ferrari team principal Stefano Domenicali expects the team to make incremental improvements to the car over the final races of the season but ruled out making drastic changes.

"There are six grands prix to go to the end of the season and clearly, we need to make a step forward in terms of performance, because we cannot rely purely on the misfortune of others," he said.

"Where we need to improve a lot is on circuits that require maximum aerodynamic downforce. Having said that, we mustn't over-react as it's better to bring a few updates that work rather than bringing in too many."