Dontavious Sears added 10 points for the Cardinals (2-1), who shot 45.1 percent from the field and hit 8 of 19 from the 3-point line.
Lamar opened the game on an 11-3 run, capped off by a Dorian Chatman fast break layup, and took a 41-23 halftime lead. Delaware State (0-4) battled back in the second half, cutting the lead to six (59-53) after a Kavon Waller jumper with 5:25 left in the game.
But a Sears 3-pointer pushed the lead back to nine on the next possession and two Kevin Booze free throws two minutes later recaptured a double digit lead for the Cardinals and put the game out of reach.
Joseph Lewis and David Mallory each scored 13 for Delaware State.