Trailing by five points at the break, the Titans (3-6) opened the second half with a 20-10 run to take a five-point lead, a lead they extended to 11 points with four minutes to play.
Steve McClellan sandwiched a jumper and a three-point play around a Michael Williams 3-pointer to push the Titans lead to 11 points with 3:59 left to play.
Horne was 9 of 11 from the floor and grabbed seven boards. McClellan added 13 points off the bench and Williams added 12 more, going 4 for 4 from the line in the final 1:23 to hold the Waves at bay.
Brendan Lane had 24 points to lead Pepperdine (5-4). The Waves were held to just eight offensive rebounds and were out-boarded by a 42-29 margin.