Ireland won the toss and chose the Chevrons to bat first.
Zimbabwe set Ireland a target of 175 after scoring 174 runs for 7 in a match highly rated batsman Sikandar Raza top scored with 82 runs (48 balls).
The bowlers then ensured the Chevrons win with a comprehensive effort with 3 wickets for Blessing Muzarabani, 2 each for Richard Ngarava and Tendai Chatara and one each for Raza and Sean Williams.
• Zimbabwe 174-7 (Sikandar Raza 82, Wessley Madhevere 22, Luke Jongwe 20*)
• Ireland 143-9 (a Muzarabani 3-23, Chatara 2-22, Ngarava 2-22)
The southern African team faces West Indies on Wednesday in their second match.
The two-time Twenty20 World Cup champions West Indies lost to Scotland by 42 runs in another big upset on Monday.