The Griffins used an 18-4 run sparked by 3-pointers from Lewis and Kevin Bleeker to lead by 10 with 7:28 left. Lehigh answered as Corey Schaefer hit a 3 and Tim Kempton added two baskets to pull within three with 1:34 remaining.
Canisius countered with Lewis' 3-pointer and hit all six of its free throws in the final minute to hang on. The Griffins shot 32.2 percent, but had six 3-pointers and went 19 of 21 on free throws.
Jamal Reynolds chipped in 12 points and seven rebounds for Canisius (2-0).
The Mountain Hawks (0-2) had a slight edge in shooting percentage, but went 3 of 15 from deep and committed 20 turnovers. Kempton finished with 19 points and Brandon Alston added 11 for Lehigh.