Dhawan top-scored with 74 off 91 on his ODI return and stitched a century stand with Rahul which was helping India score at nearly five an over before the in-form Rahul fell for 47. India slipped from there, as all of Pat Cummins, Adam Zampa and Mitchell Starc struck to leave them on 164 for 5.
The target was later chased down rather easily with a record-breaking stand from opener David Warner and Aaron Finch.
"I feel that when KL got out, that time we planned to accelerate and those four wickets we lost, that's where we lost the momentum," Dhawan said at the press conference. "From there, we were targeting 300 runs and because of loss of wickets we ended up scoring less runs on that sort of a wicket. In bowling, we could not take wickets and they outplayed us."
Dhawan elaborated on his 121-run partnership with Rahul, saying after seeing off the initial spells of Starc and Cummins, their plan was to accelerate and give India a more competitive score.
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"I feel at that time we wanted to hold wickets in hand and we were not taking extra chances in that particular phase and still we were having four to five run-rate," he said. "I knew that in a few overs we would have gone for it, like I started going for it and started to accelerate three-four overs before KL got out. That was the plan that we were going to accelerate but unfortunately KL got out in that particular over. I feel if we both were there for another five-six overs, we would have got the run rate much more higher."
The Wankhede track on Tuesday was not its usually flat self and the ball refused to come onto the bat. While there was no swing on offer, Australia's attack "bowled really well," according to Dhawan, who attributed their accuracy and discipline to the way Cummins started.
"There was a bit of moisture when we started batting," Dhawan said. "Their bowlers bowled really well. Pat Cummins bowled really strict lines to me, having that extra bounce and pace. We handled those first 10-15 overs very nicely. Where we lost four wickets in a go changed the game for us. Then, we were behind the game and we were trying to cover it. That's where we went wrong.
"They've got good quality bowlers and they've got some decent pace as well and it's a good challenge as well [for our batsmen]. We guys enjoy taking that challenge and if you look back to the World Cup, we scored 330 (352), we took them on as well. Of course, first 10 overs Pat Cummins bowled really good line and length, tight line, he didn't give much loose deliveries and with that pace it can get a bit challenging as well to score runs, especially when they're bowling in such tight areas. But that doesn't mean that we don't have any chance. Of course, we'll come up with better plans, better solutions and execute next time."