The 37-year-old Scot carded a sensational 10-under-par 61 in the second round of the Tenerife Open to jump more than 50 spots up the leaderboard into a tie for third.
The effort, which was sparked by four birdies to start, set a new course record at Golf Costa Adeje, but it wasn’t Jamieson’s lowest round on the European Tour.
That came when he signed for a 60 in the third round of the 2013 Portugal Masters at Dom Pedro Victoria Golf Course in Vilamoura.
“It all adds up to a great round of golf,” said Jamieson of his latest low score, having followed that hot start with birdies at the seventh and ninth to be out in 29.
The Florida-based player then moved to eight-under for the round with gains at the 11th and 13th before finishing birdie-birdie, taking just 23 putts.
“I did the simple things well and holed a couple of nice putts at the right time,” added Jamieson. “The five par-5s are gettable and, if you take care of business there, you are playing well.”
The 2012 Nelson Mandela Championship winner birdied all of those par-5s in his second circuit and said: “They are key this week. If you get good tee shots away on the par-5s, you’re disappointed not to birdie.”
Jamieson’s 60 was also a course record before that was beaten by Oliver Fisher when he became the first player to card a 59 on the European Tour in the 2018 Portugal Masters.
“The course record is a nice accolade and hopefully there is a trophy for it at the end of the week,” he said of setting a new one. “I’ve had a few before and never put my card on the wall at home but maybe I should.”
Germany’s Nicolai Von Dellingshausen is the surprise leader after blistering opening efforts of 64-62, sitting three shots clear of Spaniard Pep Angles, with Jamieson, Australian Scott Hend, Finn Kalle Samooja and Spain’s Eduard Rousaud on his pro debut all on on 12-under
“The biggest positive going into the weekend was that I didn’t play particularly good off the tee yesterday,” said Jamieson. “But I was much better today and only hit one shot I wasn’t pleased with. Hopefully those feelings I had today will carry over into the weekend.”
World No 571 Von Dellingshausen holed a long eagle putt at the last to storm home in 29, having earlier picked up five birdies on the journey for home.
“Just another great day in the office,” said the 28-year-old, who holds a Challenge Tour card. “I don’t know whether it’s the course, but I’ve been working on staying in the present a lot more.
“I’m a thinker, so I like being more in the future or in the past. It’s a big challenge to stay in the present moment – I think I’ve done that a lot better the last two days.”
Grant Forrest (66) sits joint-20th on eight-under, with Richie Ramsay (67) the only other Scot to make it to the weekend on six-under as the cut fell at four-under.