Harvard (2-1) pulled ahead on a 17-0 run and outshot the Owls 51.9 percent (28 of 54) to 36.8 percent (21 of 57).
Evan Cummins grabbed 10 rebounds and the Crimson outrebounded FAU 37-23. Saunders, the 2014 Ivy League Player of the Year, also had two blocks and a steal.
FAU led 11-4 on a layup by Massey, but Harvard scored 17 unanswered points to take a 38-20 halftime lead.
Moundou-Misi hit a jumper and a dunk to put Harvard up 53-33 at 10:56 in the second half. FAU cut the lead to 13 at 56-43 on a dunk by Justin Raffington, but Harvard pulled away on a 13-3 run.