An unbeaten century from Zimbabwean captain Mary-Anne Musonda trumped 88 from Irish captain Laura Delany as the hosts won the tour opener by four wickets in Harare.
The win was a historic one, as it was Zimbabwe's first One-Day International fixture having only obtained the status in April this year.
Chasing what looked a challenging 254, Zimbabwe lost two early wickets to Sophie MacMahon and a Georgina Dempsey deflected run out to leave them in trouble at 25 for 2.
Musonda though delivered for her side - her classy innings featuring a number of flowing cover drives as she hit nine boundaries in her unbeaten 103 from 114 balls.
She received excellent support throughout, sharing partnerships with Ashley Ndiraya (24), Pellagia Mujaji (16), Josephine Nkomo (25) and Precious Marange (27) as the win was achieved with over six overs remaining.
Laura Delany on her way to 86. Pic Zimbabwe Cricket Board.
The Irish bowling unit looked rusty as they sent down 31 wides and 5 no-balls in what was in truth a poor display, badly hampered by Orla Prendergast not being able to bowl.
Cara Murray did claim two wickets, while the other successful bowlers were Sophie MacMahon and skipper Laura Delany.
Having been put in to bat, the Irish fielded four ODI debutants - Prendergast, Amy Hunter, Georgina Dempsey and Celeste Raack.
Ireland got off to a solid start with Gaby Lewis (24), Rebecca Stokell (22) and Leah Paul (13) all getting going as they reached 96 for 3.
A fourth wicket stand of 76 between Laura Delany and Shauna Kavanagh (31) really put Ireland in the ascendancy.
Delany hit nien fours in her fluent 86 from just 81 balls, and looked set to become Ireland Women's fourth ODI centurion before falling to a catch on the extra cover boundary.
Orla Prendergast (28) and Sophie MacMahon (29) both scored quickly and it seemed having posted 253 for 8, Ireland had done enough - Musonda though had other ideas.
The teams meet again at the same venue on Thursday.