Call it one of the biggest upsets of the year.

Masamichi Yabuki pulled off a massive stunner, defeating compatriot Kenshiro Teraji by tenth round technical knockout Wednesday at City Gym in Kyoto, Japan.

The time of stoppage was 2:59, as the previously unbeaten Teraji (18-1, 10 knockouts) was trapped on the ropes by the attack of Yabuki (13-3, 12 KOs), who wins the WBC junior flyweight title and ends Teraji’s four-year title reign after nine successful defenses.

All three judges had Yabuki ahead by the scores of 88-83, 86-85 and 87-84 at the time of stoppage.

The fight was originally scheduled for September 10 but was rescheduled after Teraji tested positive for COVID-19.

Teraji, 29, Teraji entered the fight as The Ring’s no. 1 rated contender at 108 pounds, below another Japanese fighter, Ring champion Hiroto Kyoguchi. Yabuki, also 29, was rated no. 10.

The win was the sixth straight for Yabuki since his last defeat, a split decision to Daniel Matellon in 2018.