Rahmanullah Gurbaz walked back to the pavilion without opening his account as Australia's players celebrate.
Ibrahim Zadran, who was the backbone of their batting effort during their historic win against England, perished for 22.
Coming at one down, Sediqullah Atal rose to the occasion, scoring a 95-ball 85 before being dismissed by Spencer Johnson in the 32nd over.
Atal’s dismissal opened floodgates as Afghanistan slipped from 159-3 to 199-7.
After putting on a match-winning all-round effort (41 and 5-58) against England, Azmatullah Omarzai scored 67 to take Afghanistan to a fighting 273.
In response, Australia's Travis Head started blazingly, smashing a fifty off just 34 balls.
Australia raced to 109-1 in 12.5 overs when rain halted play. Head was batting then on 59* off 40 balls, while Steve Smith milked 19* off 22.
Groundsmen cover the pitch as rain stops play.
Umpires Kumar Dharmasena and Alex Wharf inspect the outfield for a rain-curtailed match.
In a lighthearted moment, Afghanistan captain Hashmatullah Shahidi picks up water from the outfield as groundsmen toil hard.
Afghanistan coach Jonathan Trott waits for the rain god to relent as a washout would be detrimental to their semi-final hopes.