Central Arkansas (8-19, 5-11 Southland Conference), which trailed 61-60 with 3:56 left in the game, went on a 10-3 run to take a 70-64 lead with 1:28 remaining. Lamar could not answer.
UCA knocked off Sam Houston State, the conference's second place team, 80-71 Thursday night.
The Bears made 6 of 15 3-point attempts, while limiting Lamar to just 1 of 10 from the perimeter. UCA hit 49.1 percent of its field goal attempts.
Jalen Jackson had 12 points and DeShone McClure added 11 for UCA.
Nimrod Hilliard led Lamar (3-25, 2-14) with 19 points and nine rebounds. Amos Wilson had 16 points and Donovan Ross added 11.