Having kept themselves in the four-match series with a thrilling two-wicket win on Tuesday, the tourists dismantled the Zimbabwe batting line-up to ensure a share of the spoils in the finale.
After being bowled out for 259, Afghanistan's attack pressured Zimbabwe into an astonishing collapse in which they lost four wickets for no runs, reducing the hosts to 29-6 in the 13th over.
Zimbabwe were able to recover somewhat but, on the same day that Zimbabwe Cricket chairman Peter Chingoka reportedly stepped down from his role, slipped to a humiliating defeat as the last wicket fell with just 159 runs on the board.
Despite a five-wicket haul from Zimbabwe seamer Donald Tiripano (5-63), playing in only his third ODI, Afghanistan were still able to post a competitive total.
Wicketkeeper Shafiqullah was the key performer in the Afghan innings, passing his half-century to score 56 before Tiripano brought a fine knock to an end.
The Zimbabwe reply looked shaky from the start as Regis Chakabva (9) and captain Brendan Taylor (1) departed early.
And the game then turned dramatically in Afghanistan's favour as they ripped through the Zimbabwe middle order to take full control.
Richmond Mutumbami (64) threatened to save the match for Zimbabwe, the wicketkeeper putting on a fine 97-run seventh-wicket partnership with Timycen Maruma (29).
But his efforts proved in vain as spinner Sharafuddin Ashraf, who posted figures of 3-29, effectively ended the lower order resistance before Aftab Alam (2-30) bowled Tiripano (1) to wrap up a magnificent success.