Lawry ran for a 40-yard touchdown, and Williams threw a 9-yard TD pass to Melvin Vaughn and an 11-yarder to Lawry to help Old Dominion build a 24-14 halftime lead.
FIU (6-3, 4-2 Conference USA) pulled to 24-23 on a 9-yard run by Alex Gardner and a safety. Lawry ran in for a 1-yard score late in the third and Nick Rice kicked two fourth-quarter field goals for the Monarchs.
Isaiah Harper had three catches for 108 yards for Old Dominion (4-6, 2-4), including a 65-yard catch that set up Vaughn's touchdown run.
Alex McGough threw for 323 yards and two touchdown passes to lead FIU, including an 11-yarder with 20 seconds left. Gardner finished with 95 yards rushing.
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