The home side ran in seven tries in the encounter with flyhalf George Whitehead kicking six conversions to make it two wins from three this campaign.
Griquas raced into a 14-0 lead after 20 minutes when Dylan Maart and Zane Bester went over for five-pointers and Whitehead making no mistake from the kicking tee.
The visitors hit back when replacement Aden da Costa scored a try after good line-break by left-wing Jared Africa while Jurie Matthee was successful with the conversion.
The hosts took a commanding 21-7 advantage into the halftime break after Caleb Abrahams his team's third try of the afternoon.
It was more of the same after the interval as Cebo Dlamini was put into space and dived for Griquas' fourth five-pointer of the match.
Western Province stayed in the contest after an opportunistic score by veteran hooker Scarra Ntubeni after the home team had fumbled the ball behind their tryline.
The men from Kimberley though made sure they took maximum points by running three more late tries to seal a dominant victory on home soil.
The Lions were left to rue ill-discipline and missed tackles in their narrow 25-27 loss to Griquas in the Currie Cup Final at Ellis Park on Saturday, says coach Mzwakhe Nkosi.
George Whitehead slotted a last-minute penalty to give Griquas a dramatic 27-25 victory against the Lions at Ellis Park and a first Currie Cup trophy in 55 years.
Springbok Quan Horn will captain the Lions alongside Bok behemoth Asenathi Ntlabakanye in their Currie Cup final against the Griquas at Ellis Park on Saturday.
The Lions will contest Saturday's Currie Cup final against Griquas at Ellis Park with a new captain, following hooker PJ Botha's injury withdrawal.
