The Reds, with Senne Lammens making his debut in net, stormed into a two-goal lead, through composed finishes from Mason Mount and Benjamin Sesko.
Robin Roefs in the Sunderland goal kept the score down at times, while Lammens also produced key saves in each half to enable United to keep a first clean sheet of 2025/26, in Amorim's 50th game in charge of the club.
Here’s how Ruben reacted to ‘a good, but not perfect’ performance in his post-match interviews with MUTV, BBC Sport and more…
WE WERE GOOD, NOT PERFECT
“Of course it’s so much better to win games.