The Cardinals (19-4, 8-2 Atlantic Coast Conference) followed up Monday's upset of No. 2 North Carolina with a lopsided win despite uneven stretches. The absence of leading scorer Damion Lee (bruised knee) impacted their rotation, but plenty of teammates stepped up to fill the void.
Several baskets by Lewis midway through the second half help spark a 10-0 run that got Louisville back out to a comfortable lead en route to keeping the Eagles (7-16, 0-10) winless in league play.
Donovan Mitchell added 10 points, Quentin Snider and Jaylen Johnson each had nine and Chinanu Onuaku added eight with 13 rebounds.
Sammy Barnes-Thompkins scored 11 points for Boston College before fouling out.
