Rising Japanese star Kaoru Mitoma struck a hat trick after coming off the bench in the second half on Saturday, sparking Royale Union Saint-Gilloise to a 4-2 comeback win over Belgian top-flight opponent RFC Seraing.

Entering after the break with Union trailing 2-0, Mitoma quickly helped the home side shift the momentum at Brussels' Stade Joseph Marien.

He put Union on the board in the 55th minute with his first Belgian league goal, receiving a through ball at the left of the area and finishing from a tight angle across Seraing keeper Guillaume Dietsch.

With Union level from an equalizer by winger Dante Vanzeir, Mitoma put them ahead 3-2 in the 76th minute, once again gathering at the left of the box and firing into the opposite corner.

The former standout for J. League side Kawasaki Frontale brought up his hat-trick with an outstanding 90th-minute goal, dribbling from his own half past multiple defenders before beating Dietsch from the right.

Mitoma transferred in August from reigning J. League Kawasaki to Premier League side Brighton & Hove Albion, who immediately loaned him out to Brussels-based Union, co-owned by Brighton chairman Tony Bloom.

A member of Japan's Olympic men's soccer team, which finished fourth at the Tokyo Games, Mitoma was not in the Samurai Blue squad for its recent Asian World Cup qualifiers against Saudi Arabia and Australia.