WHEN Iain Duncan Smith told his doubters never to "underestimate the determination of a quiet man" it was the beginning of the end of his disastrous tenure as leader of the Conservative party.

So Luke Donald would be well advised not to issue a similar sort of warning to his rivals at either the Scottish Open this week or the Open Championship next week. Yet, the rest of the fields at Royal Aberdeen and Royal Liverpool should certainly be concerned about the capabilities of the unassuming Englishman.

As Rory McIlroy hogged the limelight on the opening day with a course-record 64, Donald stole almost unnoticed on to the leaderboard in his usual understated fashion. His opening 67, though, was still highly impressive. As a brisk north-westerly wind buffeted those who ventured out on the Balgownie links, he did not surrender a single shot to par. Only one other player in the 156-strong field, Kristoffer Broberg, matched that feat. The Swede, though, had been in the first group and played in the most forgiving conditions.

Donald's flawless four-under-par effort left him in a share of fifth place, just three shots adrift of McIlroy, and handily placed to add to his haul of victories. He has won multiple events on the European Tour and the PGA Tour and became the first player to top the money lists on both circuits in 2011. He also spent a lengthy stint on top of the world rankings around that time. The 36-year-old is still widely regarded as an underachiever, though, because of his record in the majors. His best finishes have been ties for third in the Masters in 2005 and the US PGA in 2006.

On neither of those occasions was the man from Hemel Hempstead ever seriously in contention entering the back nine of the tournament on the Sunday afternoon. With his disappointing displays in the majors in mind, he enlisted the services of Chuck Cook, who coached Justin Rose to the US Open title last year, to make sweeping changes to his swing. Donald, who won the Scottish Open at Castle Stuart in 2011, believes he is finally starting to see the benefits of that radical surgery and is now a more complete player.

"I always used to struggle when the wind was from left to right," he said. "I struggled to hold the ball into the wind. Now I feel more comfortable doing that. Windy days are easier with my new method. The changes have been beneficial.

"I have been working with Chuck for coming up to a year now and I feel I am about 90 per cent there. You have to build slowly, but I feel more comfortable with every week.

"I was very happy with my score. It certainly wasn't easy out there, so to be bogey-free was satisfying. Everything is heading in the right direction. It has been a choppy season for me. I want to get some momentum back again this week. I want to shoot some low scores, have a round where I am really firing on all cylinders."

Donald was joined by Phil Mickelson on his first round and the reigning champion would have equalled his playing partner's score had he not three-putted the final green to mar an otherwise excellent outing. However, the American was content with how he fared in the sort of conditions with which he would once have struggled and the way he launched the defence of his title.

"It was a hard-fought round," he said. "I fought hard and played well in tough conditions. In particular, I had, apart from at the last, a very good putting day.

"It was challenging putting in cross-winds, but I produced 17 great holes of putting. It was a good first day and it would have been fun had I not finished with a bogey.

"I am surprised to see some of the low scores because the wind was pretty strong and the fairways are tight. It is a great test of links golf and a great way to get ready for the Open."

Mickelson feared that he had inadvertently incurred a one-shot penalty on the 10th fairway when the ball moved as he prepared to address it. "I couldn't really figure out what had happened," he said. "I only saw it in my peripheral vision. I was focusing on a point a foot in front of the ball, where I wanted to extend my divot to. I asked Bones [his caddie, Jim Mackay] if it had moved and he wasn't sure either. But the ruling was that the wind had moved it from the hillside."