With Steven Smith (25 not out) solid at the other end, Australia reached 83 for one in 16 overs.
Mortaza also praised Tamim Iqbal for his brilliant 95-run knock which helped Bangladesh to reach near 200-mark, he said, "Tamim has performed consistently well for us including back to back centuries in his past 3-4 innings".
In the end the Tigers failed to build any real momentum and would surely have tasted defeat if not for the weather coming to their rescue. Australia has gained one point after a rain-affected game while Bangladesh hasn't opened its account yet.
Starc said there was continued frustration among the bowling brigade about the white Kookaburra ball not swinging in games, as they had expected it would. Only four more overs were required to get a result via the D/L/S method, but it wasn't to be.
Legspinner Adam Zampa, preferred to John Hastings by the selectors, picked up two wickets with Travis Head, Hazlewood, Pat Cummins and Moises Henriques grabbing one apiece.
Earlier, a sensational death bowling spell by Mitchell Starc (4/29) trumped Tamim Iqbal's superb 95 as Australia bowled Bangladesh out for a paltry 182 in 44.3 overs.
Ably supported by Smith, Australia got themselves into prime position, before the rain intervened.
"It's about trying to get that win to get through to that next stage, but to also try and find a few weak points in some of their players heading into the summer as well".
Beaten by England last week, Bangladesh must win to keep their last four hopes alive. "Everyone that bowled I thought did a pretty good job today", Smith said.
Unfortunately for Australia, who bowled out Bangladesh for 182, the rain became heavier and the match was called off at 2019 GMT.
If they win the game against archrivals England, they have nothing to worry, but if Bangladesh beat New Zealand and England win their two remaining matches, against Australia and New Zealand, the Aussies are out, with Bangladesh going through.
The left-hander achieved the feat against Bangladesh in Match 6 of the tournament where he scored an unbeaten 40 runs in a tie marred by rain. "The groundsmen, they perhaps could have shown a bit more urgency being a big tournament".
Starc rocketed back to form after a lacklustre first-up effort against New Zealand, scorching the Bangladesh tail-end with searing pace and accuracy and re-discovering his pinpoint yorker to take four wickets in just nine balls.