INDIANAPOLIS - Joe Flacco connected with Michael Pittman Jr. for a 10-yard touchdown pass with seven minutes to play and Julian Blackmon had a critical interception as the Indianapolis Colts beat the Tennessee Titans, 20-17 at Nissan Stadium on Sunday afternoon. The win was the Colts' first win in the AFC South this season as they improve to 3-3. Flacco started at quarterback again for Anthony Richardson, who is battling an oblique injury he suffered in a week four win against Pittsburgh. Flacco finished 22 of 38 for 189 yards, 2 touchdowns and an interception. The Colts jumped out to an early lead with a 10-play, 70-yard drive on their first possession capped by a Flacco to wide receiver Josh Downs 22-yard touchdown. The Colts' defense forced a three-and-out on Tennessee's first possession to give the ball right back to the offense, but Flacco threw an interception to safety Amani Hooker. The Titans cashed in the takeaway as Will Levis found former Indiana Hoosiers' receiver Nick Westbrook-Ikhine for a nine-yard touchdown to tie the game at 7. The two teams swapped field goals to make it a 10-10 game at halftime. Tennessee ate up almost nine minutes of clock in the third quarter on a 14-play, 70-yard drive. Running back Tony Pollard broke free for a 23-yard touchdown run on 3-and-19 to put the Titans on top, 17-10. The Colts cut in the Tennessee lead with a 22-yard Matt Gay field goal on the first play of the fourth quarter before Pittman's game-winning touchdown catch. Levis was looking for Calvin Ridley deep when Blackmon intercepted the second-year quarterback to preserve the 20-17 lead. Richardson appeared to be on track to play this week, practicing three days with full participation on Thursday, but he was designated as the third quarterback on Sunday. Running back Jonathan Taylor missed his second straight game with an ankle injury, while wide receiver Pittman Jr. played after news broke this week he may have to go on the injured reserve list with a back issue. Center Ryan Kelly left the game with a calf injury. The Colts return home next week to host the Miami Dolphins (2-3) at 1:00 p.m. on FOX59.