Afghanistan won the toss and opted to bat first. They added 83 runs in the first wicket stand which is now the highest first-wicket partnership in the series so far.
Hazratullah Zazai, who has been struggling in the series, fell as the first man scoring 31 off 24.
After the tremendous first-wicket stand, Afghanistan continued losing wickets. They lost eight wickets while scoring the last 68 runs.
Rahmanullah was the best among the Afghan batsmen today. He ended up scoring 61 off 47 with four fours and as many sixes.
For Zimbabwe, pace bowler Chris Mpofu bagged four wickets conceding 30 runs, which is now his best bowling figure in T20 Internationals.
Tinotenda Mutombodzi took two wickets.
Zimbabwe are already out of the race for the final, which will be played on September 24 between Afghanistan and hosts Bangladesh at Sher-e-Bangla National Cricket Stadium.