Italy's Francesco Laporta carded a superb bogey-free 9-under 63 to leap into a one-shot solo lead after 36 holes at the Abu Dhabi Championship, while stars America's Bryson DeChambeau, Ireland's Shane Lowry and England's Danny Willett missed the cut.
Laporta, 29, was at 4-under for the day before putting together a blistering run of five birdies on the final five holes to card the best round of the week so far.
"I gave myself a lot of opportunity for birdies and so when I had the opportunities, I took it," Laporta said. "Every time I was putting for birdie, I made it. It was a great day," Laporta said.
The Italian is bidding for his first European Tour victory this week after missing the cut in the two tour events he has played this season.
England's Matthew Fitzpatrick also put together a late run of birdies to manage a second-round 67. The Englishman is tied in second place, four shots off the lead, alongside Spain's Rafael Cabrera-Bello.
World No. 1 Brooks Koepka, who started the day tied in third, had a second-round to forget, struggling to three bogeys and two double-bogeys on his way to carding 75.
American Koepka is playing his competitive return after three months out with a knee injury that forced him to miss the President's Cup in December.
A string of stars missed the cut in Abu Dhabi, including DeChambeau, who made a bogey and two double-bogeys to finish the second-round with a 5-under 77.
Information from Reuters contributed to this report.