Overnight leader Ryan Fox, Matthieu Pavon and Erik van Rooyen shared the halfway lead at the Irish Open on Friday as putting woes left tournament host Rory McIlroy seven shots off the pace.

New Zealand's Fox, son of All Blacks World Cup-winning flyhalf Grant, sank three birdies on the back nine to card a three-under-par 69 and take the clubhouse lead at eight under

He was joined by Frenchman Pavon after a second consecutive 68 while South African Van Rooyen left it late, finishing with back-to-back birdies in a course-record 65 to make it a three-way tie atop the leaderboard.

Sweden's Joakim Lagergren carded a 68 to finish one shot behind the trio at Ballyliffin Golf Club and one ahead of a group of players including Britain's former U.S. Masters champion Danny Willett.

Three British Open places are up for grabs for the leading players in the top 10 who are not exempt, and with South African Van Rooyen already qualified for Carnoustie, Fox, Pavon and Lagergren remain in contention heading into the weekend.

It was another difficult day for world number eight McIlroy, who mixed three birdies with four bogeys on his way to a 73.

The 29-year-old Northern Irishman's long game was largely impressive but he admitted he must improve on the greens to stand a chance of repeating his 2016 win in the tournament at the K Club.

"I've hit the ball well from tee to green which is something I was struggling with the last couple of weeks so I'm more comfortable with my swing," McIlroy said.

"It does depend on what the guys do this afternoon but I'd say if I shot two 68s over the weekend, I don't think I'd be too far away. Getting to double digits I think is a great target."