Graeme McDowell and Shane Lowry in strong position after opening 66s

Former US Open champion Graeme McDowell enjoyed a welcome return to form on the opening day of the Scottish Open on Thursday.

McDowell’s sole top-10 finish on the European Tour this season came back in February and he missed the cut when bidding for a third successive French Open title last week, a second round of 78 being his worst score in 32 rounds at Le Golf National.

The 35-year-old admitted he needed to “clear his mind” of thoughts about technique and looked to have succeeded with an opening 66 at Gullane, which was marred only by bogeys at the last two holes.

“It’s always disappointing to finish with a couple of bogeys but I played some good stuff today,” said McDowell, who carded four birdies in succession in a front nine of 30 and also birdied the 16th before three-putting the 17th and 18th.

“I drove the ball well and the putter was quite spicy the first 11 or 12 holes before cooling down, but I would have taken 66 before going out and I will take it now.”

McDowell revealed he and coach Pete Cowen had found the solution to his poor form by looking at videos of his swing from 2010, the year he won the US Open at Pebble Beach and holed the winning putt in the Ryder Cup at Celtic Manor.

“I’m trying to get back to basics and we have narrowed my stance and used my body to swing the club how I used to,” McDowell added.

“And it was nice to get back on a course that gives you a few opportunities in benign conditions. I just need a few low numbers to get my belief and confidence back and today will go a long way towards that.”

Shane Lowry is likely to carry a lot of Irish hopes into St Andrews after his fine recent form and the Offaly golfer also finished his first round of 66 after a flawless first round that saw him pick up two birdies in the first three holes and making gains on the 10th and 16th after teeing off in the afternoon groupings.

American pair Rickie Fowler and Matt Kuchar also started their Open warm-ups on the front foot by joining the group on four under, with Justin Rose also making a fine start at Gullane.

Denmark's Thorbjorn Olesen had set the clubhouse target on seven under after a flawless 63, one ahead of England's Daniel Brooks. Seven golfers carded five-under-par rounds, among them another American Ryder Cup player in Jimmy Walker.

In a week dominated by Rory McIlroy missing his British Open defence due to an ankle injury suffered playing football, Olesen could sympathise with the world number one after injuring himself getting off a camel in Dubai last year.

“When I had to get down I pulled a muscle in my groin and it took a few weeks before I could walk properly again,” Olesen admitted with a smile.

The 25-year-old also discovered a tendon problem in his left hand over the winter but battled on for four events – missing the cut in the last three – before undergoing surgery at the start of February.

“It’s been a tough time but I keep working on the right things and hopefully it will come,” said Olesen, who lost a play-off for the Mauritius Open in May in his first event back after three months on the sidelines. “I showed today I can still shoot low rounds.

“I hit almost every green – only missing the 18th – and hit a lot of fairways and greens today, which was the key.”

Two birdies in the final five holes helped Pádraig Harrington card a two-under 68, a shot ahead of Damien McGrane in the clubhouse, while Michael Hoey shot a level-par 72.

Former Ryder Cup captain Paul McGinley got off to a disastrous start, finding himself on four over after two holes following a triple bogey on the opening hole and a bogey on the second. Four more bogeys and two birdies added up to a six-over 76 for the Dubliner.