The Northern Irishman’s hole-in-one on the 214-yard eighth was the clear highlight on a mixed session for the US Open runner-up, who finished two-under-par on a day of low scores.
It was McIlroy’s first ace in competition since he made one in Abu Dhabi on the European tour in 2015.
Meanwhile, McCarthy shot the lowest round of his career after setting a blistering early pace with four straight birdies to open his tournament. He added five more without dropping a shot en route to a score of 10-under-par.
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