The victory runs the No. 3 ranked Bearkats' season record to 10-0 and earned Sam Houston its first ever undisputed Southland Conference football championship.
Flanders rushed 20 times for 145 yards including a 15 yard touchdown. Sincere gained 75 yards on 11 carries and earned 102 yards on three catches.
Sam Houston took just 2:20 to put points on the board as Sincere completed a five-play 82-yard drive after the opening kickoff with a 36-yard touchdown run up the middle.
Flanders tallied on a 15-yard run with 14:54 to play in the second quarter, completing a seven-play 80-yard drive.
Craig Alaniz kicked a 38-yard field goal after a Gary Lorance fumble recovery to give the Bearkats a 16-0 lead with 11:38 to play before half.
On the Demons' next possession, Darnell Taylor returned a interception 38 yards for a score as Sam Houston took a 23-0 lead.
Anthony Gilbert produced the only first half points for the Demons recovering a bad Bearkat snap in the end zone for six points. John Shaughnessy added the extra point as Sam Houston took a 23-7 lead into intermission.
Bell hit Flanders for a 35-yard pass and run on Sam Houston's first possession of the second half four minutes into the third quarter.
Shaughnessy was successful on his school record 12th consecutive field goal from 34 yards with 7:24 left in the third to cut the Bearkat margin to 30-10.
Sam Houston scored two plays later after a 43-yard run by Flanders and a 12-yard touchdown by Sincere. Sincere tallied his third touchdown three minutes later on a 62-yard touchdown pass from Bell.