Yamamoto and Hirakawa were battling over third place on lap 27 of 37 when the pair made contact at the Turn 11 right-hander, the result of Yamamoto making a late lunge to the inside.
Impul man Hirakawa was tipped into a half-spin but otherwise was able to continue, but Yamamoto was only able to get far as the start/finish straight before his damaged front-left suspension gave way, forcing him out of the race.
