In reply to Sri Lanka’s 6-157, Stoinis struck an unbeaten 59 off 18 balls to get Australia over the line with 21 balls to spare.

Stoinis pummelled four fours and six sixes to reach his half-century in just 17 balls, bettering the previous Australian record of 18 balls set by David Warner.

But as grand as the knock from Stoinis was, the match increased concerns about the form of skipper Aaron Finch, who scored an unbeaten 31 off 42 balls in one of the scratchiest displays of his decorated career.

Finch was in struggletown early as he inched his way to four runs off his first 15 balls.

The 35-year-old was so bemused by one Lahiru Kumara delivery that he quipped to the umpire: “Happy to take any ideas if you know how to hit that”.

There were 21 dot balls and no boundaries off the bat during the six-over power play as Australia crawled to 1-33.

Sri Lanka’s early efforts were all the more meritorious given that pace star Binura Fernando limped off after just five balls with what appeared to be a hamstring injury.

But the arrival of Glenn Maxwell changed the contest.

Maxwell cracked 22 runs off his first six deliveries as Australia plundered 47 off three overs to move to 2-85 after 10.

His momentum was stifled in the 12th over by a series of brutal Kumara deliveries in which Maxwell was battered and bruised.

The Victorian was left writhing in pain after being struck on his right hand.

Two balls later, he copped a direct hit to the throat from a rising Kumara delivery that was clocked at 141km/h.

Players immediately rushed to Maxwell’s aid as he took a few steps before slumping to his hands and knees.

He was assessed for several minutes before being given the all-clear to continue – albeit with a huge red mark on his throat.

The incident rattled Maxwell, and he was out a short time later for 23 off 12 balls courtesy of a brilliant catch on the boundary from substitute fielder Ashen Bandara.

His dismissal brought Stoinis to the crease, and the West Australian throttled Australia over the finish line in the most brutal knock of his career.

“Once I got in, the plan was to just keep going,” Stoinis said.

“To be honest I was really nervous today, being at home in front of lots of family and friends here.

“But I’m really happy that we ended up putting on a bit of a clinic there.”

Australia’s preparations for the must-win match hit a hurdle when spinner Adam Zampa was struck down by COVID-19.

Under new rules Zampa could have still played, but Australia decided to err on the side of caution by playing Ashton Agar instead.

Australia entered the match under pressure following their 89-run loss to NZ last Saturday, effectively making their remaining four pool matches must-win affairs.

New revelations about the 2018 Sandpapergate affair were also unwanted distractions.

Fit-again opener Pathum Nissanka (40 off 45 balls) and Charith Asalanka (38 not out off 25 balls) top scored for Sri Lanka in an innings that only really got going at the death.

Mitchell Starc (1-23), Josh Hazlewood (1-26) and Agar (1-25) were economical, but Cummins ended with an expensive 1-36 after being taken for 20 runs in the final over.

-AAP