Andrea Dovizioso bolstered his chances of overhauling Casey Stoner for third in the MotoGP world championship but was essentially unhappy with fourth place at Motegi.
The Tech 3 Yamaha rider is now just five points behind reigning champion Stoner in the points standings with three races remaining.
However, Dovi – who was promoted to fourth place after team-mate Cal Crutchlow ran out of fuel on the final lap – was disappointed with how the weekend unfolded in Japan.
“It's hard to be satisfied with this fourth place and there are a few reasons why, he said.
“First of all I was not as fast as I believe I should be. It was actually a strange weekend because of the problems with the brakes.
“This track is so hard for braking that we worked a lot and tried many things to solve that problem.
“But at the beginning of the race the brakes did not work properly and I did not understand why and I had to keep some margin in the corners, as I could not stop as I normally do,” Dovizioso explained.
“After a few laps it started to get better and I could push more and more but I had already lost a lot of time.”
The Italian also admitted he was unable to find his usual ultra-smooth rhythm as he attempted to close the gap to Alvaro Bautista and Crutchlow.
“I did not ride as smooth as I wanted as well, so I could not catch up to Alvaro and Cal,” he said.
“It's a pity because I expected more from this weekend, so I suppose fourth is not so bad.
“Now I'm looking forward to going to Sepang next week where I am confident I will be battling for the podium again.”