All the 2010 runners-up managed was a try by hooker Scarra Ntubeni which fly-half Demetri Catrakilis converted before kicking a penalty to leave his side trailing 22-10 at half-time.
Few pundits gave a Lions side containing just one Springbok, in lock Franco van der Merwe, a chance despite a shock one-point away win over fellow-South Africans Central Cheetahs last weekend.
Stormers started with six Springboks, including three in the back row and skipper and centre Jean de Villiers, plus a new lock in Argentine Puma Manuel Carizza.
But the visitors had no answer to the ceaseless tackling of the Lions, who took virtually every scoring chance they had with new scrum-half Faf de Klerk impressive.
"Unbelievable,'' said Lions skipper and No.8 Warren Whiteley. "I am so proud of my boys and our supporters.
"We do not worry what others say about us - we focus on our opponents and all we thought about this week was the Stormers.''
A shattered De Villiers offered no excuses: "This performance was a disgrace. There was no desire, no commitment. We all need to have a long, hard chat.''
Whiteley set up Watermeyer go dive over just 105 seconds into the first half and Boshoff converted, kicked two penalties and two drop goals for a 19-0 lead on 20 minutes.
De Villiers opted to kick for touch instead of at goal soon after and it paid off with Ntubeni dotting down after a maul and Catrakilis converted.
A penalty each from Boshoff and Catrakilis closed the first-half scoring in perfect late South African summer conditions.
Stormers camped in Lions territory for much of the second half, but it was Boshoff who kept the scoreboard operator busy as he slotted three more penalties and a third drop goal.
-AAP
