The Reddies, 1-1 overall and 1-0 in the GAC, ended a six-game road losing streak to the Bisons dating back to 1988.
The Reddie defense accounted for four scores including a pair of fumble returns.
The Reddie offense was stagnant in the opening 30 minutes totaling just 62 yards.
Trailing 7-0 in the second quarter following a Chaz Rogers 1-yard run for the home team, HSU's Benny Anderson picked up a fumble and went 41-yards untouched to put the Reddies on the board with 7:41 to play in the half. Charles Gonsalves added the point after to tie the score at 7-7.
The Bisons, which attempted just two passes last week, regained the lead 20 seconds later as Rogers hooked up with Jeremy Holt for a 63-yard score.
The defense again set up the Henderson's next score as Robbie Aldridge forced and recovered a fumble at the Bison 31 with 5:40 left in the half.
Henderson scored five plays later as Turell Williams went untouched from 4-yards out, but Gonsalves missed the point after and Harding still led 14-13.
The Reddies had one last chance in the half to take the lead, but the Bisons forced a Henderson punt.
Christian Latoof booted a 50-yard punt and Holt fumbled the ball at the 16. As time ran out in the half, Keaton Stigger picked up the ball and rumbled into the end zone to give the Reddies a 20-14 halftime lead.
The HSU offense continued to have problems to begin the second half and after a punt, Harding went 70 yards on five plays capped off by a 2-yard run by Kale Gelles to give Harding a 21-20 lead with 10:34 to play in the third. Gelles set up the score with a 59-yard run down to the seven, three plays earlier.
The Reddie defense came up big again as Stigger forced Rogers to fumble with Marquie Russell recovering the loose ball at the Bison 26 to set up Henderson's go ahead score.
Nathan Nall then hit Nick Johnson with a 21-yard scoring strike with 5:03 left in the third quarter. The Reddies elected to go for the two-point conversion, and Nall hit Jazz Scott to make the score 28-21.
Henderson's offense then responded putting together a 10-play 85-yard drive capped off by an 8-yard pass from Nall to Williams with 12:29 to play in the game.
With 7:27 left to play following a 27-yard Latoof punt down to the Bison 9, Harding began driving. The Reddies, however did not give up the big play as the Bison drove 73 yards on 21 plays only to be denied on 4th-and-7 as Jeremy Rodenburg and Maxie Graham stopped Kelvin Martin to put the game away for the Reddies.
The Reddies totaled just 189 yards of offense with Nall completing 19-of-29 passes for 173 yards.
Harding fumbled the football eight times, losing the ball four times with all leading to Henderson scores.
Graham had 10 tackles for the Reddies, while Taylor Stone and Keaton Stigger each had nine stops. Stigger also had a tackle for a loss, a forced fumble and the fumble return for a score.
Henderson will play its first home game of the season next week when the Reddies play host to Southwestern Oklahoma State, Saturday at Carpenter-Haygood Stadium beginning at 6 p.m.