The fourth day witnessed heated conversations between the two captains, Tim Paine and Virat Kohli, in Perth as Australia were strengthening their grip on the match. During the wicketless first session, the captains even came into physical contact when Paine ran down the pitch for a single in the 71st over of the innings. As Paine nudged the first ball of the over towards midwicket for a run, Kohli ran towards the pitch in anticipation of collecting the ball and collided with Paine before the batsman could reach the non-striker's end. Even as Kohli collected the ball and made his way towards mid-on for the next delivery, Paine followed him for a couple of steps for a few words before umpire Chris Gaffaney interrupted to remind them they were the captains.

Kohli to Paine: "I'm not saying a word to you, why are you getting riled up?"
Paine to Kohli: "I'm fine. You're the one that lost it yesterday, why are you trying to be cool today?"
Chris Gaffaney: "Oi, that's enough, that's enough."
Paine: "We're allowed to talk."
Gaffaney: "Nah, nah, come on, play the game. You guys are the captains."
Paine: "We can have a conversation... there's no swearing, no..."
Gaffaney: "Tim you're the captain."
Paine: "Keep your cool, Virat!"

When Paine was walking off after being dismissed for 37 eight overs later, Kohli said a few more words that made the Australia captain turn around for a reply.

Kohli and Paine had earlier been recorded exchanging words after a caught-behind appeal against Australia's captain was turned down on the third evening. Walking past Paine, Kohli had remarked to his team-mates "If he messes it up, it's 2-0", moving Paine to retort "You've got to bat first, big head".