The Cape side entered the match in a comfortable position to earn a place in the knock-out stages, and they made sure of it as they broke away in the second half to secure a morale-boosting bonus-point victory.
The first half was uneventful as both teams ran hard at one another on attack but neither of them threatened to score a try, which resulted in the only points scored being compliments of penalty goals, with ASM Clermont Auvergne slotting over two to one by the DHL Stormers.
However, the hosts dominated the second half as they scored four tries to one by the visitors to snatch the victory.
DHL Stormers flyhalf Kade Wolhuter had an opportunity to kick the first points of the match in the 10th minute, but his penalty goal attempt went wide, while his Clermont counterpart Anthony Belleau kicked two within 12 minutes for a 6-0 lead in the 26th minute.
The DHL Stormers showed intent on attack as the match progressed, but mistakes combined with the solid defence denied them from capitalising on it. The only points they scored in the half was a solitary penalty goal by Wolhuter in 37th minute, which saw them trail 6-3 at halftime.
The Capetonians struck first after the restart as Wolhuter kicked his second penalty goal four minutes into the half to level the scores at 6-6, but this was cancelled out as Belleau kicked his third penalty goal soon after.
ASM Clermont Auvergne were dealt a blow soon after as Belleau received a yellow card for a deliberate knockdown whereafter Springbok No 8 Evan Roos, who came on as a replacement for the hosts, capitalised on this with a try from a powerful leg drive from a maul, which handed the DHL Stormers the lead for the first time in the game.
They added their second try in the 51st minute as wing Suleiman Hartzenberg broke through on the outside and popped the ball to replacement scrumhalf Herschel Jantjies, who stretched over the chalk, and centre Dan du Plessis dashed through a gap in the defence minutes later to hand the hosts an encouraging 25-9 lead.
The visitors narrowed the gap seconds into the final quarter as Argentinean wing Bautista Delguy darted through the defence, and the successful conversion pushed their score to 16 points, but the home side responded strongly with a try by utility forward Deon Fourie from a rolling maul for their bonus point try.
The hosts received a yellow card in the dying minutes as replacement back Sacha Feinberg-Mngomezulu received his marching orders, but neither team were able to add to their score in the final minutes of the clash, which saw the DHL Stormers earn their third victory in fourth matches, emerging 30-16 victors.
DHL Stormers 30 (3) – Tries: Evan Roos, Herschel Jantjies, Dan du Plessis, Deon Fourie. Conversions: Jean-Luc du Plessis (2). Penalty goals: Kade Wolhuter (2).
ASM Clermont Auvergne 16 (6) – Try: Bautista Delguy. Conversion: Gabin Michet. Penalty goals: Anthony Belleau (3).