Having already been eliminated from the competition, Clermont left most of their frontline stars at home for this weekend's trip to South Africa, and paid the price in the second half as home side piled on 36 unanswered points, having only led 14-12 at the break.
The Sharks were missing a few big names of their own, including Grant Williams, Andre Esterhuizen, Edwill van der Merwe and Ethan Hooker, but still had more than enough firepower to pull away from their opponents in the second half.
The victory lifted the Sharks into fourth place in Group A, but needing fifth-placed Toulouse to lose at home against Sale Sharks to hold on to the final qualification spot for the knockout stage.
The Sharks made a fast start in sweltering Durban conditions, with Aphelele Fassi crossing early after a clever attacking move from a lineout. Clermont hit back through wing Joris Jurand, before Jaden Hendrikse finished neatly down the blindside to restore the hosts' advantage.
Despite dominating territory and possession for long spells, the Sharks went into the break holding only a slender 14-12 lead after a costly loose pass allowed Kylan Hamdaoui to race away for an opportunistic Clermont try.
Any hopes of an upset were quickly extinguished after the restart, as the Sharks emerged with renewed intensity. Vincent Koch powered over from close range to set the tone, before PK Sobahle finished brilliantly in the corner to stretch the lead.
With Clermont tiring rapidly, the floodgates opened. Fassi grabbed his second after a quick tap penalty, Siya Masuku added another following sustained pressure, and Phepsi Buthelezi produced the standout moment of the afternoon with a stunning 60-metre solo effort.
The Sharks were not finished there, with Jurenzo Julius crossing in the dying moments to bring up a half-century of points and cap a ruthless second-half display.