New Harlan (7-1) got 93 yards on eight carries from Marcus McMillian and 66 yards on seven rushes from Cody Taylor.
The Patriots fumbled the ball three times in the first quarter.
"It was pretty ugly. The kids were having trouble with their long sleeves, but we got rid of that at halftime," said New Harlan coach Scott Caldwell.
Eric Miller scored the Bobcats' lone touchdown with 4:24 remaining in the second quarter. New Harlan's Andrew Dozier stopped Joey Broughton on the two-point conversion run.
As time expired to end the first half, McMillian broke tackles and scored on a 52-yard touchdown run. Taylor added the two-point conversion to make it 8-6.
"Defensively, I was fairly happy in the first half," said Caldwell. "We made them work for what they got, but we couldn't get anything going offensively."
Both teams turned the ball over once in the third quarter.
New Harlan used a six-play, 54-yard drive to score as McMillian capped the drive with a 16-yard touchdown run with 4:25 to play in the game.
Dozier recovered a fumble as New Harlan took over on the Bell 22. Six plays later, Austin Maggard found Jordy Brewer for a 1-yard touchdown pass with 35 seconds remaining.
Bell County lost Broughton to an injury in the first half. The fullback returned briefly in the third quarter, but left the game and didn't return.
"We lost out linebacker there before the half and they took advantage of that," said Bell County coach Bert Marcum. "He's the heart and soul of our defense, and when he went out our defense went out."
"I'm not taking anything away from the New Harlan Patriots. They're a well-coached football team. They got after us hard tonight."
Ryan Collett led Bell County (15-5) with 52 yards on eight carries. Miller added 13 yards on six rushes.
The Bobcats were held to 49 yards of offense.
"They lost a key player," said Caldwell. "He's a big boy. They do a lot of their offense around him.
"It made it a little easier on us offensively, and we were able to move the ball."
Tucker Lewis powered the New Harlan defense with six tackles. Tyler Grubbs followed with five tackles. Andrew Dozier and Stephen Dozier recorded four tackles apiece.
Both coaches were pleased with the overall year.
"We had a wonderful team," Caldwell said. "I want to thank the parents for letting me coach their young boys. They all improved this year."
"We had a good season," said Marcum. "We won the league in Tazewell (Tenn.) and came in second here."
Harlan beats Lynn Camp for third place
The Harlan Green Dragons took third place in the fifth- and sixth-grade playoffs by defeating Lynn Camp 14-8 in the consolation game.
Harlan (7-5) lit up the scoreboard first as Dustin Hensley bulled his way into the end zone from 2 yards out on the first play of the second quarter. The touchdown was set up by a 40-yard pass from Ty Saragas to Vince Bianchi.
The Wildcats responded quickly. On the fourth play of their ensuing possession, Lynn Camp's fullback broke free for a 42-yard run. The Wildcats added the conversion to take an 8-6 lead.
The lead was short-lived, however, as Ty Saragas took the ensuing kickoff 68 yards to put Harlan back on top. Dalton Overbay ran for the conversion to set up the final margin.
Lynn Camp (6-5) threatened to reclaim the lead twice, but the Dragons forced turnovers as Bianchi hauled in an interception in the second quarter and Christian Turbyfill recovered a fumble in the third.
Hensley led the Dragons on the ground with 12 carries for 53 yards. Saragas completed three of nine passed for 61 yards, including two catches by Bianchi for 41 yards.
Hensley and Jesse Napier each recorded six tackles for the Dragons. Bianchi and Dylan Chasteen each recorded five tackles, and Justin Morrisett added three. Dakota Morris, Jared Fuson, Saragas, Overbay and Zach Hollins each had two tackles, and Turbyfill added one.