Ireland survived an inspired spell of swing bowling from Zimbabwe's Tinashe Panyangara to scrape through for a three-wicket win on the last ball of their group B encounter in Sylhet on Monday.
Chasing 164 for a St Patrick's Day victory, the associate nation seemed to be cruising against their test-playing opponents after opener Paul Stirling's 34-ball 60.
Stirling hit nine boundaries and a six and with captain William Porterfield (31) added 80 runs for the opening wicket but Panyangara's double strike in the 15th over brought Zimbabwe back in the game.
Panyangara (4-37), who was taken for 18 in his first over by Stirling, also dismissed the dangerous Kevin O'Brien (17) in the 18th over and returned to bowl the final over of the innings with Ireland needing just four runs for victory.
In the final over, Ireland lost Ed Joyce (20) to Panyangara and Max Sorensen to a run out off successive balls but managed to scamper for a bye off the last delivery for the winning run with wicketkeeper Brendan Taylor missing a run out.
Earlier, captain Taylor (46-ball 59) hit six fours and two sixes and anchored Zimbabwe's batting as his team posted 163 for five in their twenty overs after being put in to bat.
Elton Chigumbura hit 22 off 13 balls with two sixes in the last over to take Zimbabwe to a competitive total after Irish spinners George Dockrell (2-18) and Andy McBrine (2-26) restricted them in the middle overs.