Sediqullah Atal and Azmatullah Omarzai hit half-centuries to help Afghanistan set Australia 274 to win in their winner-takes-all Champions Trophy clash on Friday.
Atal scored a 95-ball 85 with six fours and three sixes before Omarzai boosted the total at the end with a 63-ball 67 at Gaddafi Stadium in Lahore.
The Afghans were bowled out for 273 after exactly 50 overs.
The winners will secure a top-two finish in Group B and a place in the semi-finals.
Batting first after winning the toss in overcast conditions, Afghanistan lost opener Rahmanullah Gurbaz for nought in the first over to Spencer Johnson.
Ibrahim Zadran, hero of Afghanistan's win over England in the first match with the highest-ever Champions trophy score of 177, added 67 for the second wicket with Atal before he fell for 22 to spinner Adam Zampa.
Atal and skipper Hashmatullah Shahidi (20) put on 68 for the fourth wicket before Australia fought back with four wickets for just 40 runs.
At 199-7 Afghanistan were in danger of being dismissed for a below-par total but Omarzai held the innings together, smashing five sixes, adding an invaluable 74 runs with the last three wickets.
Rashid Khan chipped in with a 17-ball 19 with two boundaries.
Ben Dwarshuis was the best Australian bowler with 3-47 while Zampa took 2-48 and Johnson finished with 2-49.
sh/jc
