The splendid morning’s work – she was out in the opening group alongside compatriot Catriona Matthew as the local legend hit the symbolic opening shot in the first women’s professional tournament to be staged at the East Lothian venue – left Duncan sitting joint-third, two shots behind pacesetter Hinako Shibuno from Japan.
Duncan was playing as an amateur in the 2021 edition and went on to thrill the home fans by securing a share of tenth spot on her major debut, also picking up the Smyth Salver as the leading player from outwith the paid ranks.
The 22-year-old is a professional herself now, having only made her debut in last week’s Trust Golf Women’s Scottish Open at Dundonald Links in her native Ayrshire.
Not surprisingly, Duncan looked a little tentative in that outing, but not on this occasion. In fact, she was on the front foot from the off in the season’s final major and did herself proud.
Her two opening two drives were mighty blows, the second one leading to an early birdie as she wasn’t too far away from holing her approach at the par-4 second.
Watched by her mum, one of her brothers, her fiance and a posse of others, the 2021 R&A Women’s Amateur champion once again looked very much at home on one of the biggest stages in the game.
She also birdied the par-5 fifth before then seeing her early momentum halted by back-to-back bogeys, her one poor swing of the day doing the damage at the sixth before she then totally misjudged using a putter from off the green at the next.
The way she regrouped, though, was very impressive indeed, especially when you consider she is playing this week with way more pressure on her shoulders than a year ago in Angus.
A third birdie of the day, this one from around 20 feet, at the par-4 eighth took her out 35 before she then produced a beautiful nine holes of golf coming home as the gallery started to swell all the time.
Guided expertly by European Tour winner and her former Stirling University performance coach Dean Robertson, Duncan didn’t really miss a shot coming home and the only surprise was that she had to settle for three-under 32 over that stretch.
She birdied the 11th from around feet, should have picked up another shot after a majestic approach to four feet at the 15th then eagled the 17th from five feet before signing off by giving herself another birdie chance from the left rough. That went abegging, but it was still a fine performance.
“It was worth the 4.30 alarm,” said a smiling Duncan afterwards. “I wouldn't be happy if it wasn't worth it. I'm glad it's over with and I played well. I didn't take it too seriously this morning. I just went out and enjoyed my warmup.”
She’d joked on Wednesday about Robertson’s on-course chat normally being “mediocre”. But she admitted: “It was more mediocre for me this morning, cracking jokes. But it was a relaxed morning considering how early it was and I think that's kind of what helped me shoot that score.”
Last week’s disappointment had actually helped. “I got a wee bit down on myself last week,” she admitted. “My head was down. I just wasn't in a good mood, to be honest. But today I was in a good mood and played well.”
She may be willowy, but Duncan packs a punch with a driver in her hands. “I've kind of been struggling with the driver recently,” admitted the young Scot. “I got a new head in it and that seemed to have sorted the lefts and the rights. Yeah, really happy with driver.”
What are her numbers? “Clubhead speed ranges from 102 to 104. Maybe it was a wee bit more today. Maybe I was a wee bit more pumped up,” she said as the talk turned technical. “Then average distance, if it's a good one, it will carry 245 and it will bounce for miles out here. But I'm not a very technical person. I get confused easily. I try to keep it simple.”
Robertson, one of the top performance coaches in the business, came up with something on this occasion that helped her enjoy an equally pleasing day on the greens, both in terms of putts holed and her pace putting.
“Dean's helped me a lot this week,” she admitted. “He's introduced a lot of breathing techniques and, though it sounds weird, I breathed quite well today. Just try to keep it relaxed. I get a bit uptight. Because I want to hold it so badly.”
After starting with a double-bogey 6 then doing likewise after turning for home, Matthew had to settle for a five-over-par 76. “Apart from that, I actually played quite well, so a little frustrating,” she admitted.
At the same time, Scotland’s most-successful woman professional heaped praised on the country’s rising star. “Louise played great - great round from her,” observed Matthew. “She kept it very steady, didn't get into any trouble and took advantage of the par 5s.”
Shibuno, who was dubbed the ‘Smiling Cinderella’ as she landed this title at Woburn, finished second in the LPGA Tour’s Lotte Championship earlier in the year but had missed the cut in her last six events, including last week’s Trust Golf Women’s Scottish Open at Dundonald Links after rounds of 71-75.
A best-of-the-day 65 that was sparked by three birdies at the start and contained eight in total was more like it from the 23-year-old. "I was looking at the leaderboard and remembering the past,” she admitted. “It's rare to be in a position like this. It takes me back (to 2019), it really feels like that."
Defending champion Anna Nordqvist had to settle for a 74 after dropping three shots coming home, with 2020 winner Sophia Popov and newly-crowned Scottish Open champion Ayaka Furue also having a fight on their hands to be among the top 65 and ties following matching 75s.