But despite enjoying the best of the conditions, the 28-year-old could only card a two-over-par 74 at Dundonald Links to end the day nine shots behind Finland’s Mikko Ilonen.

McIlroy followed a missed cut in the US Open with a tie for 17th in the Travelers Championship, but then made an early exit from the Irish Open at Portstewart, where he was the defending champion.

The four-time major winner has not missed successive cuts since May 2015, but recent work on his wedge game failed to reap dividends as he followed bogeys on the 11th and 12th - his second and third holes of the day - by dumping his approach to the 13th into the burn which guards the front of the green.

The resulting double bogey was at least followed by a first birdie of the day on the par-five 14th, but another bogey on the 18th - where he pitched into a greenside bunker - took McIlroy to the turn in 40.

Birdies on the third, fifth and seventh repaired most of the damage, only for a bogey on the ninth to leave McIlroy at the wrong end of the leaderboard in the £5.4million event.

WATCH: Where is it going wrong for Rory McIlroy? Rich Beem analyses his erratic opening round at the Scottish Open https://t.co/O1ML1PHpme pic.twitter.com/YATPp9GkPa

— Sky Sports Golf (@SkySportsGolf) July 13, 2017

Ilonen has missed the cut in his last four events, but a new set of irons helped the five-time European Tour winner card seven birdies in a bogey-free 65 to lead by two shots from Rickie Fowler, Ian Poulter, Padraig Harrington, Paul Peterson, Callum Shinkwin and Andrew Dodt.

"I wasn’t imagining shooting 65," Ilonen said. "I thought anything in the 60s would be a great round. Given my recent form, I think red numbers (under par) really, but seven under is a good start."

Playing alongside McIlroy, 2015 champion Fowler carded five birdies in a bogey-free 67 as he maintained the form which has produced a win and five other top-10s this season.

"It’s a lot of fun to be back here at the Scottish Open," Fowler said. "It was unfortunate I had to miss it last year with the schedule and the Olympics being part of the summer, but I’m excited to be back.

"It’s been a good year so far, very consistent, being in contention the first two majors. It was not what I wanted on the Sundays there, especially at Augusta, but it was better at the (US) Open.

"I just didn’t get anything to go and Brooks (Koepka) played a hell of a round there to win the tournament."

Poulter described his game as a "work in progress" despite five birdies and a tap-in eagle in his 67, the 41-year-old’s recent upturn in form including qualifying for the Open last week.

"I will have zero expectations again next week because when you do, you often get a nice surprise," said Poulter, who was second to Padraig Harrington the last time Birkdale hosted the Open in 2008.

Harrington’s 67 was completed as the forecast rain belatedly arrived and included what he described as a "minor miracle" on the 16th and a chip-in for birdie on the next.

"We were very lucky to find the ball on the 16th and my provisional was in a bunker," the three-time major winner said. "I was staring at a seven but managed to take a penalty drop, get it up near the green and hole the par putt from around 90 feet."

Richie Ramsay and Stephen Gallacher led the home challenge on four under, with Gallacher trying to emulate Ramsay and fellow Scot David Drysdale’s achievement in Ireland last week by claiming one of the three places available at Royal Birkdale via the Open qualifying series.

"The goal for the last three weeks has been to make it to Birkdale and this is my last chance," Gallacher said. "It’s a great start and something to build on for the rest of the week."

Open champion Henrik Stenson started his round with a triple-bogey seven after needing three attempts to hack out of heavy rough, but recovered to card a level-par 72.