The Pirates (11-5, 2-1 Conference USA) trailed 69-60 with 8:18 remaining but outscored Houston 29-9 down the stretch. Richmond scored 11 of his points in that span, including three of his four 3-pointers.
It was the second consecutive come-from-behind victory for East Carolina, which defeated Central Florida 88-85 Saturday after trailing by 17 in the second half.
The Pirates committed just five turnovers in the game and shot 54.3 percent (19 of 35) in the second half after hitting 32.4 percent (12 of 37) in the first.
Mike Brey is looking at former Notre Dame players to fill two assistant jobs that have opened up with the departures of Martin Ingelsby and Anthony Solomon.
Purdue's 2016-17 prospects got a jolt Wednesday when forward Caleb Swanigan announced he will return for his sophomore season.
Clemson's Jaron Blossomgame says he is withdrawing from the NBA draft and returning to school for a final season.