MacIntyre, one of a record eight left-handers in this year’s Open field, made the biggest move of the European contingent. His 66 featured six birdies, with his only dropped shot coming on the exacting par-three 16th.
However, the world number 14 atoned for that bogey by knocking in a 20-foot putt from the edge of the 17th green for a birdie.
That lifted the Scot to the same score as Hatton, who was his usual animated self as he mixed four birdies with two bogeys in his 69.
“I’m in a good spot,” said MacIntyre, who finished runner-up to JJ Spaun at the US Open, with Hatton tied fourth.
“I’m not scared. I’m not going to back away. If I’ve got a chance, I’m going to roll the dice. I’ve got so much more confidence and so much more belief that I am good enough.”
The torrential rain arrived with McIlroy on the 18th green but he retained his composure to finish with a solid par, while his Ryder Cup team-mate Ludvig Aberg missed a tiddler for birdie on the last to end on two under.
English pair Justin Rose and Harry Hall are also at two under. After a bogey-free opening, Rose dropped his first shot of the championship on the par-three sixth.
He dropped three more shots on the 11th after losing a ball in a bush but two birdies limited the damage as he signed for a 71.
In-form Hall, who is emerging as a surprise contender for Luke Donald’s European team, made seven birdies and three bogeys in a 67.
McIlroy’s playing partner Tommy Fleetwood started quickly with four birdies in his opening seven holes to improve to two under.
His only bogey, at the 18th, saw him post a 68 for a one-under total that will mean the 2019 runner-up will be at Portrush for the weekend.
The top 70 and ties at the end of round two will play the final two rounds.
More to follow.
