The win gives Sam Houston State their second consecutive Southland Conference regular season football championship, a feat unequaled in the Bearkats' 26 season in the league.
Sam Houston and Central Arkansas stand as co-champions, both with 6-1 league records. The No. 3 ranked Bearkats upped their season record to 8-2.
Flanders produced the 22nd 100-yard rushing performance of his career, carrying 17 times for 138 yards including scoring runs of 56 and 4 yards.
Bell completed 17 of 23 passes for 239 yards and three touchdowns. Diller caught seven of those passes for 119 yards and a score.
The Kat defense allowed Northwestern State only 141 total yards and 42 on the ground. The Sam Houston offense rolled up 509 total yards (253 rushing and 256 passing).
The championship marks Sam Houston's fifth Southland football title. The Bearkats also won championships in 1991, 2001, 2004 and 2011.
After being forced to punt on their first two possessions, the Bearkats got rolling on a seven play 93-yard drive with Flanders scoring on a 56-run through the right side at the 3:07 mark in the first quarter. The run marked the ninth time in his career Flanders has scored a touchdown of more than 50 yards.
Ed Eagan returned the kickoff 82 yards to tie the game 7-7 ten seconds later.
Miguel Antonio gave the Bearkats a 10-7 lead with just 21 seconds into the second quarter after a 10-play 55-yard drive. Sam Houston reached the five-yard line on the drive but was moved back to the 20-yard line by a personal foul penalty.
A quarterback sack by Robert Shaw forced Northwestern State to punt from its end zone against the wind on the next Demon possession. On the first play after the punt, Bell found tight end T. J. Jones open over the middle for a 50-yard touchdown as SHSU went up 17-7 with 12:08 to play in the half.
The Bearkat defense came up with the next score. J. T. Cleveland forced a fumble that pinned the Demons on their own one. On third down, Bookie Sneed intercepted a Brad Henderson pass and returned the pick 11 yards for a touchdown and a 24-7 lead 7:54 before intermission.
The interception was Sneed's fourth of the year and his second for a touchdown. The junior cornerback now has eight career interceptions, tying him for eighth in the all-time SHSU interception standings.
Bell threw 38-yards to Trey Dillar and 10-yards to Chance Nelson for a pair of touchdowns in the final 2:57 of the first half. The pass to Diller completed a seven play 68-yard drive and Nelson's catch ended a 10 play 61-yard march.
John Shaughnessy kicked a 27-yard field goal on the last play to make the score at intermission 38-10.
Sam Houston opened the second half with a 14-play 80-yard scoring drive capped off by a four-yard touchdown run by Flanders.
The Bearkats finish their regular season schedule next Saturday at 2:30 p.m. in College Station against Texas A&M.