The youngster was on the scoresheet twice during the drubbing of the Dutch outfit, and has now netted in all three home Europa League matches in 2019/20.
Mason grabbed a brace in the clash with AZ, which helped United to seal top spot in the group and go into Monday’s draw for the knockout stages as one of the seeded teams.
After Ashley Young had put the Reds one up on Thursday night, Mason doubled our lead in the 58th minute when he latched onto James Garner’s tackle on the edge of the area, before smashing the ball beyond Marco Bizot.