Ireland 242 for 9 (McCollum 73, Tucker 56, Stirling 52, Mire 4-43) beat Zimbabwe 237 for 9 (Williams 58, Burl 53, Murtagh 5-21) by five runs
Belfast: Ireland clinched the one-day series against Zimbabwe as James McCollum's 73 and Tim Murtagh's five wickets helped secure a five-run win at Stormont on Thursday.
Thursday's result means Sunday's game in Belfast will be a dead rubber.
McCollum's 111-run opening stand with Paul Stirling (52) helped Ireland reach 242-9 as Lorcan Tucker also notched 56.
Three Murtagh wickets reduced Zimbabwe to 14-3 and while Sean Williams (58), Ryan Burl (53) and Craig Ervine (43) responded, the hosts held their nerve.
With three balls remaining, Zimbabwe required only eight runs for the win, but Mark Adair finished with a dot ball, the wicket of Burl and the concession of a single to see his side over the line.
The hosts had kicked off the three-match series with a four-wicket victory at Bready on Monday and looked on course for a comfortable win at Belfast.
A big Irish total seemed on the cards as McCollum and Stirling reached 111-0 in the 24th over before the Middlesex opener became the first of Solomon Mire's four victims.
As Kevin O'Brien and Andrew Balbirie departed cheaply, Ireland collapsed to 185-5 before Tucker's vital late innings - which included seven fours - gave the Irish attack something to bowl at.
Middlesex seamer Murtagh produced a marvellous opening spell to dismiss Zimbabwe captain Hamilton Masakadza, Mire and Brendan Taylor as the visitors slipped to 14-3.
Ervine's knock of 43 breathed life back into Zimbabwe's innings before a 69-run partnership by Burl and Donald Tiripano threatened to square the series.
However, Murtagh bowled Tiripano late in the 49th over to complete his five-wicket haul and Shane Getkate's run-out of Burl in the penultimate ball confirmed the home side's win as they secured a first home series win since 2014 and a first ever home series victory against a full member nation.