Brown, the Colts' forgotten 2009 first-round pick, scored on a 4-yard TD run with 1:56 left to give Indianapolis a 22-14 victory over Tennessee.
"Those are by no means chip shots," Andrew Luck said after another troubling offensive showing with only 264 total yards. "To have a guy like that [Vinatieri], it, well, it really makes a difference."
Indy (8-4) has a three-game lead over the Titans (5-7) with four left and a sweep of the season series. The Colts can wrap up their eighth AFC South title in 11 seasons with one more win, one more Titans loss or a tie by either team.
Coach Chuck Pagano shook up things after two blowout losses in the last three weeks. He surprised many by moving Brown into the starting lineup ahead of Richardson, the No. 3 overall pick in 2012 by Cleveland who Indy traded for in September. Pagano replaced Mike McGlynn at right guard with Jeff Linkenbach and also started cornerback Darius Butler ahead of Cassius Vaughn.
Vaughn picked off two of Ryan Fitzpatrick's 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.
Though Fitzpatrick scored on a 1-yard plunge in the first half and gave the Titans a 14-12 lead in the third quarter on an ugly 1-yard TD pass to Chris Johnson, Fitzpatrick was 21-for-37 for 201 yards with one TD. Johnson managed only 69 yards on 18 carries.
"I didn't play well. We had a shot at the end there," Fitzpatrick said. "I didn't get the job done, and it hurts. For me to come out and not play well hurts."