Paul Dunne is three off the lead at the Trophee Hassan II, where a hugely congested leaderboard sees the top 52 players separated by just three shots after the opening round.
The Greystones man carded four birdies and four bogeys in Morocco, with England's James Morrison part of a four-way tie at the top.
Morrison carded five birdies and two bogeys on the Red Course at Royal Golf Dar Es Salam to join Denmark's Lucas Bjerregaard and the French pair of Gregory Havret and Gary Stal on three under par.
Three more French players - Alexander Levy, Clement Sordet and Gregory Bourdy - were among a large group on two under, with Scotland's Scott Jamieson, David Drysdale and Duncan Stewart another stroke back.
Havret, who finished runner-up to Graeme McDowell in the 2010 US Open, said: "It's good to play under par, anything in the red here is very good on a very tough course, so I'm happy.
"This course always plays hard and since the changes a few years ago it's even harder. When the wind is changing it's not easy to find the right club.
"It's in perfect condition, the course is just in great shape and we always enjoy it here. It's definitely a test of golf. I think it's one of the toughest all season."
After 18 holes in Morocco:
— The European Tour (@EuropeanTour) April 13, 2017
🇩🇰 -3 Bjerregaard
🇬🇧 -3 Morrison
🇫🇷 -3 Havret
🇫🇷 -3 Stal
All scores: https://t.co/EN5iXVYjYc pic.twitter.com/LuKVyNZy4m
Levy has not played since finishing fourth in Malaysia in the middle of February, but showed few ill effects as he carded four birdies and an eagle in his 71.
"I've had eight weeks off, I've practised a lot and changed coach so it's nice to come back out to play a tournament," Levy said. "It's exciting to bring all that hard work over the last eight weeks back out on the golf course."
Michael Hoey is three-over after his opening 76.
Defending champion Jeunghun Wang, who missed the cut on his Masters debut last week, faces a battle to avoid another early exit after struggling to a four-over-par 77.
And former Masters champion Mike Weir, who has not made a cut since November 2014, fared even worse with six bogeys and a double bogey in an 81.
The Canadian left-hander, who defeated Len Mattiace in a play-off at Augusta National in 2003, has been as high as fourth in the world, but is currently ranked 1,895th.
