Rabada was back as No 1 after his "Player of the Match" effort of 11-150 that helped South Africa defeat Australia by six wickets in Port Elizabeth to level their four-match series at 1-1.
One of the elements that had livened up a slow day out in the middle, the brass band that has been a popular fixture at St George's Park for two decades, was asked to stop playing by umpires Kumar Dharmasena and Sundaram Ravi, who claimed they could not hear the nicks off the bat.
That is a major blow to the Proteas given Steyn's wonderful Test record against Australia - 70 wickets at 27, with a blistering strike rate of 46. Rabada contested the charge, but was found guilty and slapped with a 50% match fee fine along with three demerit points.
Those are the odds on the 2-2 series draw, which is understandably the bookies' favourite after two matches of vastly fluctuating fortunes.
Rabada was found guilty of inappropriate and deliberate physical contact with Smith on the first day.
The new ICC player rankings released on Tuesday show that Rabada has returned to number one following his matchwinning 11-wicket haul in the second Test with a career-high 902 points, becoming the fourth South African to break the 900-point barrier after Vernon Philander, Shaun Pollock and Dale Steyn.
Faf du Plessis, the South Africa captain, questioned the integrity of the International Cricket Council's disciplinary approach after Kagiso Rabada, the pacer, was banned for two Tests while David Warner, the Australia vice-captain, wasn't suspended despite his ugly row with Quinton de Kock, the South African wicketkeeper.More news: France, India launch alliance for solar energy
Rabada has accepted a second charge under 2.1.7 of the code - using language, actions or gestures which could provoke an aggressive reaction from a batsman upon his or her dismissal.
To put his incredible performance into perspective, Kagiso Rabada has achieved his fourth ten-wicket haul in only his 28th Test match.
This means Rabada has accumulated eight demerit points within a 24-month period automatically leading to a two-match suspension. Disappointingly, though, following what would go down in history as the "Rabada Test", will be a couple of "Rabada-less" Tests.
South Africa's AB de Villiers has returned to the top 10 of the ICC Test Rankings for batsmen, after his match-shaping hundred in the second Test against Australia in Port Elizabeth. I just need to just do more and more, striving for perfection.
"If I do get banned, I will have to see it as a big learning curve and not repeat the same mistake".
Rabada, who kept his aggression under control on Monday - although it's likely too late for that - also dismissed Pat Cummins and Mitchell Starc as the Australians folded in less than 10 overs of the fourth day. "I am not happy about it but time moves on", he told reporters on Monday. "I'll just get far away from the batter".