The Titans can’t stop Jacoby Brissett.
The Colts quarterback has completed 12 of 17 passes for 119 yards and a touchdown, leading Indianapolis to a 13-9 halftime lead.
Neither team has punted, with each scoring on all three first-half possessions. But the Colts got the only touchdown on an 8-yard pass from Brissett to tight end Jack Doyle.
Ryan Succop has field goals of 48, 32 and 40 yards for the Titans, and Adam Vinatieri has connected from 36 and 25 yards.
Mariota, returning from a hamstring injury that kept him out last week, went 9-for-13 for 108 yards in the first half.
The Colts have gained 186 yards to the Titans’ 152.