David Warner and Nathan Lyon have both been slammed for the way they celebrated the wicket of AB De Villiers on day four in Durban.
Former South African captain Graeme Smith has called Warner a fool, while adding Lyon may regret his unnecessary actions following De Villiers' run out at Kingsmead.
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The first Test in Durban provided a major talking point on day four when star batsman De Villiers was run out by Warner and Lyon without scoring.
Australia's vice-captain then unleashed a spray on centurion Aiden Markram, who was involved in the run out, while Lyon dropped the ball on top of of De Villiers, who was sprawled on the turf in trying to make his ground.
"The Aussies were pretty fired up at that time pushing for a victory," Smith told cricket.com.au in Durban, where Australia need just one wicket on day five for victory.
"But he (Lyon) is an experienced cricketer.
"I think he'll probably say it was unnecessary himself.
"We've got used to Davey over the years. I think the less interest you take in him the better.
"He can be a bit of a fool at times. It best just to let him be."
A number of fans took exception to Lyon's actions.
Smith warned the teams not to cross the line with sledging.
@Bj_orJulian @mcjnicholas @MikeHaysman @CricketAus I’m a big fan of Nathan— Serge (@sergasso) March 4, 2018
Lyon but it is not on to drop the ball on AB after running him out. Gloating is unacceptable. He should apologise or be punished. @SuperSportTV
That behaviour by Warner and Lyon was disgusting. And towards the nicest legend such as ABV too. Should both be banned a match - and the commentators didn't even mention it?! #SAvAUS— Phil Marchant (@PhilMar) March 4, 2018
Did Lyon really drop ball suspiciously close to de Villiers? Looks that way. TV coverage glossing over/forgetting. Expecting some tough questions post game ... hopefully an explanation, cos that looked very poor.— Mark Stevens (@Stevo7AFL) March 4, 2018
Awful running there from De Villiers and Markram. But the reaction of Lyon and Warner - overly pumped up for what was a straightforward run out - was not good. Classic them I suppose. #SAvAUS— Ben White (@Ben_Chalky) March 4, 2018
Very disrespectful of Nathan Lyon to drop the ball on de Villiers like he dd #SAvAUS— Mister Squid (@FreedomSquid) March 4, 2018
Just saw the De Villiers dismissal. Why did Lyon flick the ball at him when he was on the ground? Unnecessary, IMO. #RSAvAUS— Alex Oates (@AlexJOates11) March 4, 2018
"I think everyone that's played the game has hard moments and that's what makes the hundred from Markram so special," Smith said.
"He's had to work, he's showed great composure, the Aussies were all over him after that run out.
"Everyone wants to be competitive, people love watching that.
"I think there's always a line that you've got to be careful you don't cross."
Warner, Mitchell Starc and South Africa's firebrand Kagiso Rabada have all been involved in verbal stoushes during the four-Test series opener.
However Warner received support from an unlikely source as he sweats on match referee Jeff Crowe's assessment.
Markram, who was responsible for the De Villiers mix-up after being caught ball watching, went on to score 143 and also had no issues with the withering spray he copped.
"It's natural when you play against the Australians that there's a lot of chatter on the field," the 23-year-old opener said.
"I certainly don't mind.
"It never really gets out of line either, not a lot of swearing or things like that happen.
"There are a few here and there, but it's not the end of the world. I believe it's part of the game. That's how it should be played, nice and hard, and it makes success that bit more rewarding."
Aussie keeper Tim Paine, who was full of praise for Markram's knock that no doubt created some nerves among the visitors, laughed that Warner's words clearly didn't work.
"We spoke to Aiden about running out their best player and one of the best players in the world," the wicketkeeper said.
"Just reminding him of what he had just done, trying to get him off his game, the same as they do to us.
"Had someone had run Smithy (Steve Smith) out in our team you'd cop a fair bit of a ribbing. It was nothing aggressive ... I've seen David a lot more animated than that.
"The boys were certainly pumped up ... it was a big moment in the game."
Rabada's send-off of Warner on day three attracted the attention of both umpires, while Starc gave recalled batsman Theunis de Bruyn a gobful in Sunday's post-lunch session.
"It was good to see actually. We enjoy it when Starcy is up and about like that," Paine said.
Australia require just one wicket to take a 1-0 lead in the four-Test series after setting South Africa 417 for victory.
The Proteas are 9-293 with Quinton de Kock (81) and Morne Morkel (0) at the crease.