MI New York defended a modest total of 132/8 to win by 5 runs.
Quinton de Kock top-scored for MI New York with a well-played 61.
Romario Shepherd earned Player of the Match honors for his 3-wicket haul and a crucial late catch.
The Seattle Orcas fell short in a dramatic chase despite a brave 36-run effort from captain Marcus Stoinis.