Cummins, some six and a half years after announcing himself as a future superstar with a sparkling Test debut at age 18 in South Africa, removed de Villiers, Faf du Plessis, Temba Bavuma and Quinton de Kock in a burst of 4-7.
It was an eventful day for Cummins, whose conduct was questioned by the host broadcaster after he appeared to accidentally stand on the ball.
"Accidentally on purpose," former Proteas captain Graeme Smith quipped in commentary, inferring the express paceman was illegally looking to scuff one side of the pill.
The incident - one of many in a series stacked with dramatic cricket, spiteful spats and cantankerous claims - unfolded in front of the standing umpire.
Steve Smith delayed taking the second new ball when it was first available. It proved a smart call, with Vernon Philander edging a full delivery from Mitch Marsh soon after.
The tourists celebrated the dismissal of Philander vociferously, with umpires having a long chat with Warner afterwards.
Tim Paine had previously told Philander to "switch the phone off", sledging the paceman about last week's supposedly-hacked tweet that attacked Smith.
Keshav Maharaj offered little resistance, hitting the seventh ball he faced straight to Cameron Bancroft in the covers, but Kagiso Rabada fared much better.
Rabada finished six not out, having almost offered Smith his fourth slips catch of the day while on zero.
Rabada, whose two-Test ban for making physical contact with Smith was overturned earlier this week, was given a standing ovation when he walked out to bat.
Cummins worked both du Plessis and Bavuma over beautifully, creating apprehension in the batsmen's minds then earning the reward when they prodded forward to pinpoint deliveries.
De Kock's downfall was a loose pull stroke, with the edged flying straight to Paine.
Josh Hazlewood dismissed Aiden Markram and Hashim Amla, and would have had a third wicket if not for Lyon's dropped catch.
-AAP
To get the day's top sports stories in your inbox, sign up to our newsletter here
