The sophomore from Capaccio, Italy, scored his first two goals of the game five minutes apart early in the first half.
His first goal in the 14th minute started with a long pass from Tommy Speed. Marciano gathered the pass, beat two defenders and sent a bending shot into the left side of the goal for a 1-0 Adelphi lead.
Goal number two would come in the 19th minute as Marciano knocked in a loose ball.
The lead would grow to three in the 32nd minute when junior George Yusuff scored his first goal in an Adelphi shirt. Marciano was credited with an assist on the goal.
Marciano would secure the hat-trick in the 52nd minute off of a feed from Taylor Kaczynski of Dix Hills, who had three assists on the night.
With his three goals against Saint Michaels, Marciano now has 10 goals on the season and has scored in all but two of the nine games in which he has appeared. During his freshman season in 2018, he scored 12 goals in 23 appearances.
Freshman keeper Daniel De La Heras made the start in goal for Adelphi and stopped four shots.
Adelphi (8-0-1, 4-0-1 NE10) is back in action Wednesday when they begin a three-game road trip in Worcester, Mass., at Northeast-10 rival Assumption College at 4 p.m.