The victory for the Griffons marked their second Currie Cup First Division title - the last time they won the competition was in 2008 against the Leopards.
The Valke showed their intent early on as they worked their way into the home team's red zone within the first minute, but their hopes of earning points were dashed as they conceded a penalty.
Griffons' flyhalf Louis Strydom slotted a penalty for his team shortly afterwards to hand the hosts a 3-0 lead.
It was short-lived as Valke fullback Juan Kotze kicked a penalty almost immediately afterwards to level the scores.
Kotze kicked another penalty minutes later to push the Valke into a 6-3 lead after an encouraging attacking spell.
The Griffons hit back with an opportunistic try by scrumhalf Boela Abrahams in the 15th minute, after he picked the ball up from the base of a ruck, selling a dummy before dashing to the tryline for a 10-6 lead.
Valke flyhalf Clinton Swart reduced the gap to only one point with a long-range drop goal early in the second quarter, which bolstered their confidence.
This paid off with a try by flank Jacques Verwey in the 30th minute from a rolling maul.
The hosts came close to edging their way into the lead shortly before the break, but a knock-on cost them a potential try.
Strydom then kicked his second penalty of the half to leave his team trailing 16-13 at the break.
The Griffons had the first say in the second half as they powered their way into the Valke's 22 and spread the ball wide to wing Norman Nelson, who touched down in the corner.
Strydom had two shots at goal minutes later, but he pushed both attempts wide.
The Valke, however, forced their way back with a try by scrumhalf Anrich Richter, who spotted a gap in the defence and dashed through to nudge them back into a 21-20 lead.
Strydom attempted to force his team back into the lead with two drop goals, but both attempts were unsuccessful.
Abrahams then had a shot at goal and his attempt was successful, which nudged them into a 23-21 lead with seven minutes left on the clock.
The Valke continued to fight until the end in the hope of securing a late victory but the home team shut them out to take the title.
Scorers:
Griffons
Tries: Boela Abrahams, Norman Nelson
Conversions: Louis Strydom (2)
Drop goal: Abrahams
Valke
Tries: Anrich Richter, Jacques Verwey
Conversion: Juan Kotze
Penalties: Kotze (2)
Drop goal: Clinton Swart