As Scottish Open champion Min Woo Lee moved from a share of the overnight lead into pole position on his own at the halfway stage, Jamieson jumped into the top 15 on the back of a second-round 67 at Marco Simone Golf Club in Rome.
The 37-year-old Florida-based player, who moved to five-under after an effort containing six birdies, sits 133rd in this season’s Race to Dubai, with the top 115 after the rescheduled Portugal Masters in early November hanging on to their cards.
“I have some catching up to do as I’m currently on the wrong side of the line with regards holding on to my card,” said Jamieson, who started the campaign strongly by claiming a share of 16th spot in Abu Dhabi in January but has only managed one other top-20 finish since then.
The Glaswegian finished 31st in Race to Dubai in 2013, the year he won the Nelson Mandela Championship in South Africa, then climbed to a career-best 26th in 2017.
“If I play well this week and also next week (in the BMW PGA Championship at Wentworth), then I will take it from there,” he added of his bid to retain a spot at the top table.
Recent first-time winners Calum Hill and Grant Forrest were the only other Scots to make the cut on two-under and level-par respectively, with the former signing for a second-round 65 that contained nine birdies.
Australian Lee backed up his opening 64 with a 68 to sit two shots clear of a group that includes Tommy Fleetwood, with Henrik Stenson three behind following a double-bogey at his penultimate hole.
Former Scottish Open champion Edoardo Molinari also sits on seven-under, two ahead of his younger brother Francesco.
On the Challenge Tour, Euan Walker (nine-under) and Craig Howie (eight-under) are both in contention at the halfway stage in the British Challenge at The Belfry while Jack Doherty finished with a flourish to claim second spot behind Englishman Mitch Waite in the Studley Wood Championship on the PGA EuroPro Tour.
A message from the Editor: