McDonald made his decisive move with a birdie at the 13th before holing out for eagle at the 14th to move into pole position.

Despite climbing the leaderboard, he said he had little idea where he stood during the closing stages.

“I had no idea, to be honest,” McDonald added. “I holed the putt and then I was like, ‘Oh right, that’s me six under’. I know four under is usually round about the mark, so I was like, ‘Oh right, OK’.

“The last four holes are so hard here, 16 especially. Seventeen is a really strong par-three, so you can’t take anything for granted and you just need to hit the shots.”

McDonald insists he will head to Royal Birkdale with the same relaxed mindset that served him so well in qualifying.

“I’ve got no expectations either of playing,” he said. “I’ll just go out there and try my best.

“When I did play at Troon, it was just one of those weeks where you just want to play again.

“I did miss the cut by a shot or whatever it was, but I was just like, ‘This is such a good event. I just want to get back and play it’. I’m just delighted to do it.”

There was disappointment for the other 19 Scots in the field. Blairgowrie amateur Connor Graham narrowly missed out after finishing on two under par, while Craig Lee and Grant Forrest were a further shot back.

McDonald joins Oban’s Robert MacIntyre as the only Scots currently in the field for next month’s Open Championship.

Players who failed to qualify at Dundonald will have one final opportunity at next week’s Scottish Open, where the leading three players not already exempt will secure places at Royal Birkdale.