Chris Harris Jr. and Justin Simmons intercepted Mariota, who was sacked three times and was replaced by Ryan Tannehill after Simmons' interception led to a 2-yard touchdown run by Phillip Lindsay that made it 13-0. Tannehill was sacked four times and picked off by Kareem Jackson on Tennessee's final drive, which reached the Denver 5-yard line before two offensive penalties and a sack pushed the Titans back to the 30-yard line.
The Titans (2-4) lost for the fourth time in five games. The Broncos, who haven't allowed a touchdown in nine quarters, host Kansas City (4-2) on Thursday night with the chance to get back into the AFC West race after starting the Vic Fangio era with four frustrating losses.
Mariota came into the game as the NFL's only QB who had started every game and hadn't lost a fumble or been intercepted — although he had been sacked 22 times. Both Denver and Tennessee were 2 of 14 on third down, leading to 17 punts.
The first half featured more flags (10) and punts (11) than points (six). The Broncos took a shutout into the locker room for the second straight week. Last time, it was a 17-0 cushion against the Chargers; this time it was just 6-0 on a pair of Brandon McManus field goals, one of which snapped his streak of seven consecutive misses from 50 yards or more.
Both teams bungled their way through the first two quarters. The Broncos were whistled for eight penalties and being forced to call two timeouts on special teams. The first was with 10 men on a punt by the Titans and the second one was because the play clock was at 1 second just before McManus' 53-yarder.
Mariota threw his first interception of the season — to Harris, the 20th of his career but first this season. On Harris' runback, Denver defensive end Derek Wolfe was flagged for an illegal block. Mariota's second interception came when he stepped up to avoid another sack and lofted a pass down the middle to Darius Jennings that was picked off by safety Justin Simmons at midfield.
HALL OF FAME At halftime, Pro Football Hall of Fame president David Baker presented Hall of Fame rings to Champ Bailey and the family of late owner Pat Bowlen. Also, Bailey was inducted as the 33rd member of the team's Ring of Fame. At a ceremony unveiling his 8-foot bronze pillar Friday night, Bailey chimed in on the current state of the Broncos, saying,
"It's just growing pains. There are a lot of new people around here, a good young corps, but I expect them to turn around. That's the good thing about here, we don't stay down long." INJURIES Titans ILB Jayon Brown (groin) left the game on Tennessee's second defensive snap.
Broncos wide receiver Emmanuel Sanders sat out the second half with a knee injury. UP NEXT Titans: Host the Los Angeles Chargers on Sunday. Broncos: Host the Kansas City Chiefs on Thursday night.
Follow Arnie Melendrez Stapleton on Twitter: http://twitter.com/arniestapleton
More AP NFL: https://apnews.com/NFL and https://twitter.com/AP_NFL