Rohit, however, fell just eight runs short of a century, departing after a belligerent 41-ball 92 with seven boundaries and eight maximums as India made 212 for six after being put into bat first.
Australia made one change to the team that suffered a shock 21-run defeat by Afghanistan, with left-arm fast bowler Mitchell Starc replacing spinner Ashton Agar.
Shamsi claimed 3-27 in Sunday's three-wicket win over two-time champions West Indies as South Africa chalked up a seventh win in seven games at the tournament.
All four teams in Group 1 are still a mathematical chance to progress to the semi-finals heading into the final two matches.
If India win, they would move onto the semis with six points and Australia would remain on two points and their qualification hopes will be depend on the outcome of the Bangladesh-Afghanistan match the next day.
"To get that hat-trick in a place I was born, a place I played so much cricket, in front of my family, my friends, the atmosphere, hearing the music going and everything, a nice day," he said.
Cramped-up Glenn Maxwell's incredible double-century helped Australia snatch victory from the jaws of defeat in ICC 50-over World Cup in November, leading to Afghanistan falling just short of qualifying for the semi-finals.
A win for Australia would have sent the 2021 champions and India into the last four, but even a second hat-trick in as many matches from Pat Cummins was not enough to keep their unbeaten record at the tournament intact.
Bangladesh were the inferior side on display throughout the match and unsurprisingly suffered a 50-run drubbing.
Bangladesh will kickstart the Super Eight stage against favourite Australia on Friday at 6.30am (Bangladesh Time).
The divisive 37-year-old is looking to go out on a high with victory at the T20 World Cup in the West Indies and United States, where Australia are into the Super Eight stage.
All the officials have been announced for the upcoming Super 8s stage. USA, in their first T20 World Cup appearance, will kickstart the Super Eight stage against South Africa on Wednesday at 8.30pm (Bangladesh Time).
While the bowlers delivered excellent efforts in all the group matches, the batters -- with the exception of in-form Towhid Hridoy, one comeback innings from Shakib Al Hasan, and Mahmudullah Riyad’s few efforts -- have largely misfired.
With the Super 8s berth, the Tigers also secured a direct qualification for the 2026 T20 World Cup, to be co-hosted by India and Sri Lanka.