On a historic day at Stormont Cricket Ground, with Northern Ireland becoming the 23rd nation to host a men's Test, the home bowling attack fought back after a difficult start to take the final eight Zimbabwe wickets for 67 runs before rain brought a premature end to proceedings.
Prince Masvaure hit 74 for the tourists, but McCarthy was backed up by Andy McBrine's three-wicket haul to earn the Irish the upper hand after day one.
After Andy Balbirnie won the toss and elected to field, Zimbabwe were able to reach lunch on 85 without loss with Joylord Gumbie one run short of a fifty on his Test debut.
Gumbie would be denied a maiden half-century though after he chipped to Curtis Campher off the bowling of McCarthy.
McCarthy followed it up with the scalp of Dion Myers, but Masvaure moved to a fourth Test fifty as the tourists ended a rain-affected second session on 3-153.
Zimbabwe opener Masvaure had gone past his previous Test best of 65 when he was impressively caught down the legside by Ireland wicketkeeper Locran Tucker off Campher, which acted as the catalyst for a shift in momentum.
McBrine followed it up with two wickets in two balls with Clive Madande sent back to the pavilion for a golden duck.
The tourists were able to edge beyond the 200-run mark before Mark Adair claimed the ninth wicket and McCarthy returned to finish the innings when Tendai Chatara was caught behind.
It meant Zimbabwe were all out for 210 after 71.3 overs, but Ireland avoided a tricky batting period at the end of day one when wet weather brought an early finish.
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