Oyu started Sunday's fifth round of the season on pole and led the opening 11 laps of the race before being passed by eventual winner Ritomo Miyata on the approach to Turn 1 at the end of lap 12 of 51.
From there, Oyu was quickly reeled in by third-placed Sho Tsuboi, and went off into the gravel at the first corner on lap 14 as he tried to hang on to second.