Australian skipper Michael Clarke was fined 20% of his match fee on Monday for threatening tailender James Anderson with a broken arm, but insisted there is no animosity with England.
The home team's huge 381-run victory on Sunday was tarnished by constant sledging as frustrations boiled over, culminating in Clarke being caught by a stump microphone telling Anderson to "get ready for a broken f**king arm".
The usually mild-mannered Clarke also wagged his finger in a close-up confrontation with the England quick, one of his team's worst sledgers, with the umpires needing to step in to cool tempers.
The International Cricket Council ruled Clarke breached its code of conduct relating to "using language or a gesture that is obscene, offensive or insulting during an international match".
He admitted the offence and accepted the sanction, avoiding the need for a formal hearing.
It capped a torrid Test with England skipper Alastair Cook also upset at David Warner calling his team frightened, while singling out batsman Jonathan Trott as "weak". Cook slammed the remarks as "disrespectful".
The media lapped up the tense war of words with the Sydney Daily Telegraph screaming on its front page: "Poms Mitch-slapped as rampant Aussies bring back the sledge," referring to fast bowler Mitchell Johnson tearing through the England innings.
But Clarke said it was simply his competitive nature and had nothing to do with Australian bitterness over England's 3-0 Ashes win sealed in August.
Instead, it showed Australia were up for the fight.
"I think it is because both teams want to win so badly," he said. "I respect that there is a line and both teams shouldn't overstep that line.
"I think the rivalry and the banter on the field, it is give and take both ways. It is not one team dictating the other. It is about when you have momentum, run with it for as long as you possibly can.
"And when you don't, fight your backside off to try and get it back. In this Test match, we have grabbed the moment and tried to run with it for as long as possible."
Warner on Monday said Australia had taken the verbal fight to England to unsettle them.
"I made those comments for a reason," he told reporters at Brisbane airport. "Look, yesterday, the bounce and pace got to them again.
"It is Ashes cricket. Probably went a little bit too far with the comments, but it's cricket and now it's in the back of their mind."
Coach Darren Lehmann appeared to back the tactics, saying he was all for aggressive cricket.
"I like them playing hard cricket. I like our boys being aggressive without crossing the line," he said.
The defeat at the Gabba in Brisbane was one of the heaviest-ever in the Ashes for England with the tourists crumbling under the searing pace of Johnson to be all out for 179 late on the fourth day. They were skittled for 136 in the first innings.
With four more Tests to play, Australian selectors will stick with the same squad for the next clash in Adelaide starting on December 5, with Johnson vowing to keep bowling his fearsome short-pitched deliveries.
The fragility of England's batting will be a concern for Cook with just a two-day game in the searing heat of Alice Springs against a Chairman's XI to get it right ahead of the second Test.
"We'll go away, regroup, be honest with ourselves and come back. We've done it before. There won't be any hiding," said the defiant skipper.
But former England captain Michael Vaughan said it was not looking good.
"There are some real issues in England's top seven batting line-up," he said. "They've got a lot of soul searching to do."