Button and Kunimitsu teammate Naoki Yamamoto finished second at Suzuka, behind the ARTA Honda of Tomoki Nojiri and Takuya Izawa.

It was Button's and Yamamoto's second podium finish of the season after they finished runner-up in the season opener at Okayama last month.

The result propelled the Anglo-Japanese pair to the top of the drivers' standings, one point clear of the NISMO duo of Tsugio Matsuda and Ronnie Quintarelli.

"Yes, It's great," Button said. "You know, we really wish we won this race. The first race so close, this race so close. But it's racing and you just got to move on.

"We got some good points today and leading the championship, you can't wish for more. So very happy. My first year in Super GT. Very lucky that I have Naoki as a teammate."

Hard tyre behind temperature woes

Button struggled to get his car's Bridgestone tyres up to temperature, which caused him to briefly lose second place to TOM'S Lexus driver Nick Cassidy after the restart.

The Briton explained that his tyre woes were down to his choice of hard compound - and a switch to softer rubber in the pitstop solved the issue.

"The safety car was fine, but I was on a hard tyre so to get tyres up to temperature was very difficult because the safety car is so slow. So [it was] very difficult to keep temperature," he said.

"If I had soft tyres, [it would have been] okay. But I had a big oversteer before the straight and almost spun the car. So it's tough.

"Kazuki [Nakajima] and [Tsugio] Matsuda spun the car yesterday on cold tyres. [Hideki] Mutoh crashed on cold tyres [today] and [Bertrand] Baguette spun on cold tyres.

"It's so difficult on these cars. It's something very difficult to any other type of racing. But it's learning, it's experience. Because of my problems, we put Naoki on the soft tyres, so it worked."

Additional reporting by Tomohiro Yoshita