INDIANAPOLIS — Tennessee didn't need a study session to determine what went wrong Sunday.
It was right there for everyone to see — three interceptions, a fumble that cost the Titans a possible field goal and an inexplicable personal foul at the end of the first half.
"In the NFL, you can't do what we did. You're going to make mistakes, but when you have a chance to make plays...," coach Mike Munchak said. "The bottom line is, they finished and we didn't."
The Titans' loss gives Indianapolis (8-4) control of the AFC South. Indy has a three-game lead over the Titans and the tiebreaker with a season sweep of the Titans (5-7).
The Colts can wrap up their eighth division crown in 11 seasons with one more win, one more Titans loss or a tie by either team — making Tennessee's most likely path to the playoffs through the AFC's tight wild-card chase.
And the Titans had only themselves to blame.
Though Fitzpatrick scored on a 1-yard plunge in the first half to give the Titans a 7-6 lead and threw an ugly 1-yard TD pass to Chris Johnson midway through the fourth quarter to give the Titans a 14-12 lead, it was a mostly ugly day.
He was 21 of 37 for 201 yards with three interceptions and cost Tennessee another scoring chance when NFL sacks leader Robert Mathis stripped him of the ball on third down.
Johnson ran 18 times for 69 yards, and while the defense kept Indy out of the end zone most of the day, it still made enough miscues to keep Vinatieri busy.
"It hurts a lot," defensive tackle Mike Martin said. "We played good defense a lot of the game. But we put them in field-goal range with penalties."
Vinatieri proved he still has it and surprise starter Brown, showed he does, too.
After two blowout losses in the past three weeks, coach Chuck Pagano shook things up.
He moved Brown, Indy's 2009 first-round draft pick, into the starting lineup ahead of Trent Richardson, the No. 3 overall pick in 2012 by Cleveland whom Indy traded for in September.
Vaughn picked off two passes, and Brown continued to beat up on the Titans despite rushing for only 8 yards in the first 52 minutes. He had 46 yards on the final drive and gave Indy its only touchdown.
"I guess it was time to put something together and with the division hanging in the balance, the guys manned up," Pagano said, explaining that Brown earned a rare start and the two backs would both continue rotate. "Just like the first game down there, we were able to run the ball, chew up the clock."
Indy needed Vinatieri even more than Brown.
The soon-to-be 41-year-old resembled his much younger self, tying a career high with four field goals in the first half and matching his full-game career high when he hit a perfect 49-yarder for a 15-14 lead late in the third quarter.
His fifth field goal also equaled Jason Elam's NFL record with a 16th 100-point season, and he joined Morten Andersen as the only players to score 800 points with two teams and he tied an NFL single-game record by making four field goals between 40 and 49 yards.
"Those are by no means chip shots," Andrew Luck said after the offense generated just 264 total yards. "To have a guy like that (Vinatieri), it, well, it really makes a difference."
Without Vinatieri, the Colts might be lamenting their first back-to-back losses since December 2011. Luck was just 17 of 32 for 200 yards with no TDs and one interception.
But Tennessee kept finding ways to help its division rival.
Moise Fokou's personal foul extended the first half by one play, and Vinatieri cashed in with a 37-yard field goal. Then, after taking the 14-12 lead, Fitzpatrick's fumble led to Vinatieri's 49-yarder to give Indy the lead for good.
Fitzpatrick was picked off two more times before Brown sealed it.
"Pros grind it out," Brown said. "They take it one week at a time and just keep rolling along."
NOTES: The Titans lost two more tight ends Sunday. Delanie Walker left with a concussion in the first quarter and Collin Mooney was taken by golf cart into the locker room with what appeared to be a left leg injury in the second half. ... Indy defensive tackle Ricky Jean Francois (sprained foot) and running back Daniel "Boom" Herron (strained pectoral) should have MRIs on Sunday night, Pagano said. ... Kicker Rob Bironas joined Al Del Greco as the only Titans in the NFL's 1,000-point club.
AP NFL website: http://www.pro32.ap.org