Ireland's Niall Kearney and German Maximilian Kieffer were then at ten under but the headlines at Bernardus Golf belonged to Broberg, who has shown signs of his brilliant best in recent weeks after a tough few seasons.
The 35-year-old announced himself to the golfing world in 2012 as he won three events in four weeks on the European Challenge Tour, and within three years he was a European Tour winner at the BMW Masters.
He lost his card in 2017 and, while he regained it at the Qualifying School, hip and knee injuries contributed to him playing just 11 events between 2018 and 2020.
The four time Challenge Tour winner missed six of his first eight cuts this season but, with his fitness returning, he has made four of his last five and could create one of the stories of the 2021 Race to Dubai over the weekend.
"I am taking it one shot at a time," he said. "I have been struggling all year with injuries, so it is nice to be playing good again. It’s just golf, so taking it one shot at a time.
"I was home for a month so saw an optician for my right eye and they saw something, so I have a contact lens on that eye so now I can see the putts on the line. I am rolling it pretty good so happy with it."
He added: "I played really well today. I like to shape the ball both ways and I like to putt around these greens, it’s a lot of feels and breaks but I am hitting the ball really close so that has been key.
"It was ups and downs out there, I hit some bad shots and some really good shots but my putter is smoking hot, so I am playing some decent golf."
I have been struggling all year with injuries, so it is nice to be playing good again. It’s just golf, so taking it one shot at a time
Starting on the tenth, Broberg put an approach to 12 feet, holed a 22 footer on the next and got up and down at the par five 12th for a hat-trick of birdies.
An approach to six feet brought another gain on the 14th and, while he bogeyed the 16th, he made a birdie on the par five 18th after laying up.
Smart approaches to the second and third saw him make more progress and after he took advantage of the par five seventh, a 13 foot putt on the ninth saw him hit the front alone.
Helligkilde is playing just his second European Tour event but he looked very much at home as he put an approach to six feet at the third, made the most of the fourth and then holed long putts at the sixth and seventh.
He dropped a shot on the 11th but produced a big finish, getting inside ten feet on the 15th and 17th and hitting the green in two at the last.
Detry is still seeking his first European Tour win but has 12 top fives from his 121 events and he made a fast start with a long putt on the tenth, and up-and-down on the 12th and a tee shot to four feet at the 13th.
He birdied the 18th, fourth and seventh to make it a full house on the par fives and, while he dropped a shot on the sixth, he birdied the ninth from nine feet.
Overnight leader Kearney carded a 69 with a single dropped shot, while Kieffer went one better with a bogey free effort.