Lewis Hamilton racing at F1 Japanese GP after sealing deal to leave McLaren for Mercedes

In his first race since confirming he'll leave McLaren for Mercedes next season, Lewis Hamilton will refocus on the Formula One championship challenge at the Japanese Grand Prix this weekend.

Mercedes announced last Friday that Hamilton will replace seven-time F1 champion Michael Schumacher in a major shake-up that has Sergio Perez going to McLaren.

Hamilton has two wins and three non-finishes from his past five races, with that inconsistency leaving him in fourth place in the standings, 52 points behind Ferrari's Fernando Alonso with six races to go. He led the previous race in Singapore until he suffered a gearbox failure on lap 23 of 59 and had to retire.

"In terms of the championship, there's nothing to be really gained by analyzing the points tables," Hamilton said. "From now on it's simply gloves-off. As in Singapore, I'll come out fighting, I'll just be hoping for a better result."

Hamilton has spent his entire F1 career with McLaren — the team he first began an association with at age 13 — and won the 2008 title. But the team was unwilling to match a lucrative offer from Mercedes.

For Schumacher, Hamilton's move could mark the end of the most decorated career the sport has seen, and a three-year comeback where he failed to duplicate the success of his prime. There is speculation the 43-year-old German could replace Perez at Sauber next season.

Despite the distractions, Schumacher said he was looking forward to the Japanese GP, a race he has won six times.

"My motivation is still very high after the news from last week, especially as Suzuka very clearly is one of the highlights in the calendar for me," Schumacher said.

But Schumacher will be faced with a 10-place grid penalty at Suzuka for causing a spectacular crash with Toro Rosso's Jean-Eric Vergne during the Singapore GP.

Like Hamilton and Schumacher, Perez will be eager to get the focus back on the track after a disappointing result at Marina Bay where he finished 10th.

"After underperforming in Singapore, in Japan I am expecting our car to again be as good as it used to be and we should be strong in the high-speed corners," the Mexican driver said.

Hamilton's McLaren teammate Jenson Button won here last year. He finished second in Singapore but will drop five places on the grid due to changing a gearbox.

It's the same gearbox problem that forced Hamilton to retire in Singapore. Hamilton will get a new selector but escapes any penalty because he did not finish in Singapore.

Defending champion Sebastian Vettel won in Singapore, replacing Hamilton in second place in the standings and trailing Alonso by 29 points.

The Red Bull driver has done well at Suzuka over the years, taking the checkered flag in 2009 and 2010 and finishing third last year to claim his second straight drivers' championship.