Australia were bowled out for 146 while chasing Zimbabwe's target of 170.
After posting 169/2 on the board, Zimbabwe bundled out the Aussies for 146 in 19.3 overs to win the contest by 23 runs.
Despite the shocking loss, stand-in Australia captain Travis Head called for calm, highlighting their turnaround during the triumphant 2023 ODI World Cup campaign after a shaky start.
"We've been there before. I said at the toss, we saw it in 2023 with a few defeats and injuries. We have a few guys here who were there in India in 2023 and we'll look to navigate this situation and use that blueprint," Head stated at the post-match presentation.
While Australia’s decision to field first was questioned by the experts, Head said the move was influenced by the nature of the surface. He felt the target was achievable.
"We thought it's a good wicket. A bit tacky at the start and we thought it would be even through the two innings. Even though we only took two wickets, I thought they were a bit under par.
"But we lost early wickets and came under pressure. They played well. I still felt like we'd have taken the score and were happy to chase that.
"The feedback throughout was that it was a good wicket. We put ourselves under pressure by losing wickets. We found a partnership in the middle but we left ourselves with too many," the southpaw explained.
Australia’s campaign has also been rocked by injuries. Regular skipper Mitchell Marsh remains unavailable with a groin problem, while Tim David recently returned from a hamstring strain. Their pace resources are thin as well, with Pat Cummins and Josh Hazlewood missing due to injuries.
Australia’s next Group B match is scheduled against the tournament co-hosts Sri Lanka in Pallekele on Monday (February 16).