Australia's captain Michael Clarke has admitted he overstepped the mark in a fiery confrontation with Dale Steyn as the decisive Test against South Africa at Newlands ticked towards its thrilling conclusion, and also acknowledged a caution from the umpires about his side's treatment of the ball on the final day.

As the umpires prepared to call the start of the final hour, Steyn and James Pattinson became involved in an exchange which Clarke stepped into. His angry words to Steyn escalated the stand-off until the umpire Aleem Dar was forced to step between them. In the aftermath of victory, Clarke conceded his fault though not referring to Steyn by name. The pair spoke warmly after hostilities were ceased by the final wicket.

"You definitely had two extremely passionate teams that wanted to win this Test. There were obviously a lot of words throughout the game. Let's call it banter," Clarke said. "Do you know what? Honestly, if anybody was out of line it was me and I apologise to the opposition player I was out of line to.

"A player who I have the utmost respect for, who tries to kill me every time bat, who batted exceptionally well, and I was out of line. If any player on either team, it was me who was out of line. Let's just say he [Steyn] got me at a bad time. We just had a decision that didn't go our way that I would have liked to have seen go our way but that's the game.

"And certainly as captain of your country you've got to be able to cop that on the chin. Something was said to one of my team mates. I seem to make this mistake a few times but I jumped in after him. It doesn't matter what happened, what I said was something out of character and I apologise for that. I shouldn't have said what I said."

This was far from the only flashpoint on a final day that also featured queries over the care of the ball, a beamer delivered by Pattinson and a confrontation between Australia's players and the umpires following the reversal of a decision to give out Vernon Philander on some rather ambiguous evidence.

During the 74th over of the innings, the umpires Dar and Kumar Dhamasena called over touring captain Michael Clarke and inspected the ball while appearing to offer a caution against more bounce throws. The wicketkeeper Brad Haddin had taken to waiting for the ball to bounce until he took returns from the field, often allowing it to bounce on the pitch itself.

Several subsequent conversations were had between Dar, Dharmasena, and other Australians including Haddin and Ryan Harris. It is within the power of the umpires to impose a five-run penalty and have the batsmen choose a replacement ball of similar age if they feel "the deterioration in the condition of the ball is greater than is consistent with the use it has received".

Clarke confirmed the nature of the conversation and said his players had abided by the umpires' ruling once it had been delivered to him. "The umpires were up me about a few things. That was one of them," he said. "I always believed that if you're in the ring you should be throwing the ball on the full because it's a 20 metre throw. If the guys are on the boundary you can accept that some guys can't throw it that far.

"Whatever criticism we cop for that I'm more than happy to cop but I think our players understand there is a line and we know not to overstep that. We were asked by the umpires to make sure we were throwing the ball on the full and I think we accepted that and listened to that."

Tensions over the two teams' care of the ball has simmered since the second Test in Port Elizabeth, after which the opener David Warner openly questioned the legality of South Africa's handling, particularly AB de Villiers' use of his wicketkeeping gloves to rub the ball. The hosts gained sharp reverse swing on the fourth day as they rattled to victory.

That allegation drew heavy criticism from South African team management and an ICC fine for Warner, although Harris later repeated the accusation with the qualification that it must have been legal because the umpires did not step in. The umpires were seen talking to de Villiers on day one of the Newlands match and gesturing about his use of the wicketkeeping gloves on the ball.

Faf du Plessis added another chapter to the affair when he expressed surprise on the third evening that Australia managed to gain sharp reverse swing within 30 overs, having not achieved any deviation through the air at St George's Park. Having heard of this allegation, the tourists made their displeasure known to du Plessis on the final day, being picked up doing so on the stump microphones.

Last year, du Plessis was fined 50% of his match fee during the second Test against Pakistan in Dubai after being captured on camera rubbing the ball near the zipper of his trouser pocket.

Relations between du Plessis and the Australians were not enhanced by his contention that the visitors circled him "like wild dogs" when he chose to pick the ball up while batting on day three. Warner was heard to greet du Plessis with mock howls, before offering him a send-off when he was dismissed by Steve Smith shortly before the tea interval.