Warner has gone 10 Test innings without a half century, and is averaging just 26.07 in his last 27 trips to the crease in the longest format.
He was out for a first ball duck in the first innings of the first Test against South Africa at The Gabba before managing just three in the second, albeit on a green pitch where the majority struggled with the bat as Australia won by six wickets inside two days.
Should he score 78 or more in the second Test at the MCG, Warner will become just the eighth player to score 8,000 Test runs for Australia, and he promised to take on the Proteas bowling attack in the Boxing Day Test.
"I know when I'm at my best, I'm taking the bowlers on," he said. "It goes well and it flows with the team and the guy at the other end. Now I've probably gone a bit more responsible and trying to put the team into a good position without playing a bit rash.
"If anything I can probably be a bit more aggressive and go back to the older me, take them on a little bit more. But I think that also is dictated from what wickets you are getting.
"You don't want to have a dig at the curators, but the last two years our wickets have been green. If I go out there play a cover drive and nick one, you guys [the media] will have a feeding frenzy.
"But now I'm in good positions and I'm nicking off, that's the nature of the beast. This might be a wicket where I can go out and play like the old me. So you have to adapt to those conditions that's what I've been doing the last 18 months."
In what will be the 100th men's Test between Australia and South Africa, the hosts' selectors have a tough decision to make on whether to recall Josh Hazlewood, who has recovered from a side strain, or retain Scott Boland, who took a combined 4-42 in the first Test.
Australia must keep their Head in Melbourne
The pitch in the first Test in Brisbane was labelled "below average" by the ICC, though Travis Head was still able to muster 92 from 96 balls in the first innings, a crucial contribution that made a key difference.
Although he was out for a first ball duck in the second innings, it was immaterial as Australia eased to victory shortly after, and the man of the match will be keen to show his worth again in Melbourne.
Landmark looms for Elgar
South Africa captain Dean Elgar was not happy with The Gabba surface, but will be hopeful of scoring more than the combined five runs he managed in the first Test.
Elgar is just 24 away from becoming the eighth player to score 5,000 runs for the Proteas in men's Tests, though his Test batting average in Australia of 18.4 is his lowest in any country.
After bowling out the South Africans for 189 on Boxing Day, Australia started Tuesday's play at 45-1 and piled on another 341 runs.
They were led by Warner in his 100th Test, as he survived some adversity and went on to post 200 before retiring hurt as his persistent cramps worsened in the blisteringly hot MCG conditions.
He reached his 200 in 254 deliveries, joining Joe Root as the only other player to score a double ton in their 100th Test.
Marnus Labuschagne was run-out for 14 following a mix-up during an overthrow, bringing Steve Smith to the middle, and he made his way to 85 off 161 deliveries before edging to the slips as Australia looked to up the run-rate.
Travis Head continued the high-action style with 48 not out from 48 deliveries, capping a 155-run third session to reach stumps at 386-3, leading by 197 runs.
Anrich Nortje was the visitors' most efficient bowler, with the right-arm quick in taking 1-50 from his 16 overs.
Australia could face some headaches with their bowling stocks in the second innings, with Cameron Green being forced to retire hurt after copping a bouncer on the finger, which immediately swelled up and ended his day on six runs.
Green's status for the second inning is in doubt, while Mitchell Starc's finger injury has already ruled him out of the third Test, implying he will not be able to continue bowling.
Labuschagne gives Warner a lifeline in milestone Test
Warner's day could have looked very different had Labuschagne not opted to fall on his sword.
With Warner on 47, he took an easy single, before calling for a risky second on an overthrow. Labuschagne had run through the crease on the first run, and by taking off for a second, it meant whoever was heading to the bowler's end had no hope.
Luckily for Warner, it was Labuschagne who made the turn and charged back unsuccessfully, departing after only 14 runs.
It was Labuschagne's fifth Test run-out, and since his debut no player has more in the format. Root, Babar Azam and Tim Southee all have four.
Aussies handle the heat
With temperatures in Melbourne hovering around 37 degrees Celsius, it was the Australians who handled the conditions in the draining second session.
In a completely one-sided period of play, the duo of Warner and Smith piled on 97 runs without a wicket from the 27-over session, racing to the lead and building a winning platform.
A depleted Australia batted first in Lahore, and their total of 313-7 proved beyond Pakistan's reach, despite Imam-ul-Haq making 103.
Head was the main Australian aggressor with a brilliant 101 from 72 deliveries that propelled the tourists to 171 by the time he was dismissed in the 25th over, with captain Aaron Finch (23) having played a supporting role in an opening partnership of 110.
Ben McDermott provided support with his maiden ODI half-century, though Australia lost three wickets for 21 runs in the space of seven overs as McDermott (55), Marnus Labuschagne (25) and Alex Carey (four) fell.
A flurry from Cameron Green, who hit four boundaries in a knock of 40 not out from 30 balls, gave Australia a competitive total to defend.
Fakhar Zaman was dismissed for 18 in the fifth over of Pakistan's reply, but Imam and skipper Babar Azam steadied the innings before the latter was trapped lbw by Mitchell Swepson.
Babar's steady 57 from 72 balls summed up Pakistan's issues, though, with the hosts unable to match the required run rate early in the innings.
Quick losses of Saud Shakeel (3), Mohammad Rizwan (10) and Iftikhar Ahmed (2) further damaged Pakistan's chances, despite Imam's fine work in reaching his eighth ODI century.
Imam's ton included nine boundaries, but he was then bowled by Nathan Ellis, shortly after Pakistan passed 200 with just five wickets down.
Zampa bowled Hasan Ali and Mohammad Wasim to bring up 100 ODI wickets and then moved onto 101 when Khushdil Shah lofted to Carey, with Swepson rounding things off.
Travis makes headway
It took Head just 70 deliveries to reach his second century in a 50-over match, which is the eighth-quickest in the format by an Australian batter, and the fastest against Pakistan by an Australian in an ODI.
His stay came to an end when he hit Shah to Iftikhar, while he also contributed to the bowling attack with figures of 2-35.
Zampa gets his ton
Dropped in and out of the attack by Finch, Zampa bowled superbly to finish with four wickets for 38 runs, becoming the 18th Australian bowler to take 100 ODI wickets.
While the pick of the bunch for Pakistan was Haris Rauf (2-44), Zampa spearheaded Australia as the tourists kept Pakistan's big hitters Imam and Babar – who became the second-fastest Pakistan batter to reach 4,000 ODI runs – scoring at a slow pace.
