Martin Kaymer surged into contention for his first victory in four years as several of Europe's star names, including Graeme McDowell, rediscovered their top form in the Italian Open.
Kaymer, whose last win brought him a second major title in the 2014 US Open, carded a second round of 63 at Gardagolf to finish 11 under par, a shot ahead of McDowell, Danny Willett, Thomas Pieters, Rafa Cabrera-Bello and home favourite Francesco Molinari.
But after another day of low scoring, the entire field will be separated by just seven shots heading into the weekend, with the halfway cut falling at four under par.
"It's been a while since I played that solid," Kaymer said after a round which included five straight birdies from the 13th.
"I think I was getting very close recently but that positivity was missing on the golf course because I haven't had a lot of good results.
"It doesn't matter if you've won majors and had the situations I had at the Ryder Cup, it's really exciting to be in a position that you can win a golf tournament again."
McDowell's last win came in 2015 and he was named as a Ryder Cup vice-captain last week, but the former US Open champion has not given up hope of qualifying for the team instead after missing out in 2016.
"My head will be down this weekend and I will be grinding really hard," McDowell said after a 66. "There's a lot of really great players in this field.
"I'll have to play well to win. It would do a lot for me, would do a lot for my summer, a lot for my Ryder Cup bid and a lot for my confidence in general."
Former Masters champion Willett reached a career-high of ninth in the world after claiming his first major title at Augusta National in 2016, but has since plummeted to 462nd after struggling with injuries and a loss of form.
The 30-year-old had missed the cut in all but one of his nine starts in 2018, but added a 67 to his opening 65 and has yet to drop a shot this week.
"I haven't made a cut for a while so to actually be this side of the leaderboard is pretty nice," Willett said.
"I've been working really hard and I've not been getting any results and you just have to keep your head down and hope that you get a couple of days like this under your belt."
Molinari's second consecutive error-free 66 means he has now gone 80 holes without a bogey, his last dropped shot coming on the 10th hole of the second round during his BMW PGA Championship victory at Wentworth.
"I'm trying not to think about it," insisted Molinari, who is seeking a third victory in his national Open.
"In the end, it's better to make a bogey and a few more birdies. I'm trying to stay aggressive and do my best.
"It's a course where a lot of people are up at the top of the leaderboard, so it's going to be I think a bit of a birdie-fest at the weekend and I need to be ready for it."