Jenson Button reckons Sebastian Vettel in the pound seats after closing within four of the Championship lead.
In recent weeks the Red Bull racer has been the driver to beat as his team introduced a double-DRS design of their own, giving Vettel the impetus needed to take the win in Singapore and again in Japan.
The Suzuka victory was undoubtedly a commanding one as Vettel was untouchable while his main rival in the title race, Fernando Alonso, retired on the opening lap.
The reigning World Champion's third victory of the season, matching Alonso in number of triumphs, has put him just four points behind the Spaniard with five races to go.
It was also, Button believes, puts him in pole position for the Championship.
"They've been competitive for many races," said the McLaren driver.
"In Suzuka they took another step forward, yes, and they had some new parts on the car. Obviously the (double-DRS) but I don't really know how much that helped them.
"You would say at the moment that Sebastian and Red Bull are in the best position to fight for the Championship. They're very, very strong. But you can never discount Ferrari and Fernando.
"They could bring something here which gives them a couple of tenths, or three or four tenths, and then they are back at the front again."
As for his own chances of winning the World title, Button concedes McLaren have a better shot at beating Red Bull to the Constructors' crown.
McLaren are 41 points adrift of the reigning World Champions in the teams' battle.
"We could claw that back in one race in one race, that's the great thing - if we both get a good result and those two don't. The Constructors' is definitely on," he said.
"When I get out of the car at the end of the race and I look at the points, that's the bit I really look at.
"The Drivers' is such a slim opportunity. If it happens, it happens. But I'm not going to get too excited about it."
