Rory McIlroy overtook fellow 2023 Ryder Cup hopeful Matt Fitzpatrick at the top of the 2022 DS Automobiles Italian Open leaderboard after using the last of the daylight on Friday evening to complete a second-round 66.
The World Number Two was playing the 18th as the hooter sounded to announce play had been suspended due to fading light but he opted to finish up, and holed his birdie putt to move to nine under par and open up a one-shot lead.
Afternoon starter McIlroy made a stunning eagle, six birdies and three bogeys as he treated the fans at Marco Simone Golf and Country Club to some world-class golf.
First-round leader Fitzpatrick produced a second-round 69 which contained five straight birdies to get to eight under, having earlier returned to put the finishing touches to his first round.
Tom Lewis was alone in third on seven under after making eight birdies and two bogeys in his second-round 65.
Victor Perez was then on six under, one clear of the large group containing Europe's Ryder Cup Captain Luke Donald, who himself impressed as he took a closer look at next year's host venue and several prospective team members.
The later starters will complete their second rounds on Saturday morning.
Having saved par at the short fourth courtesy of a stunning flop shot, McIlroy made his first birdie of the day from ten feet at the fifth.
He then produced good par saves at the sixth and seventh before making his first bogey of the day on the eighth.
The Northern Irishman bounced back with a close-range birdie at the ninth before giving the shot straight back on the next hole.
But after birdieing the 11th from four feet, he made an eagle on the 12th to jump to seven under.
A monster birdie putt at the 14th pulled him alongside Fitzpatrick at the top of the leaderboard but he bogeyed the 15th as the light began to fade.
A five-foot birdie at the 16th earned McIlroy a share of the lead once more and after quickly parring the 17th, he got up and down for a closing birdie as the darkness closed in.
McIlroy said: "I played a little bit better today, especially on the back nine. I took advantage of some of the more birdieable holes.
"Obviously looking forward to the weekend.
"I short-sided myself a couple of times and was able to play some good shots and get myself out of it and holed the putts.
"A few areas to try and tidy up but overall, a few good par saves which you always need.
"Fitz has had an unbelievable year, first Major Championship and he's obviously matured into one of the best players in the world. Looking forward to going up against him over the weekend."
Fitzpatrick started his second round from the tenth tee and opened with a bogey after failing to get up and down from a greenside bunker.
But he made amends at the 11th, sending his approach shot in close before holing the birdie putt.
He made another close-range birdie at the long 12th before taking advantage of the par-three 13th for a hat-trick of gains.
The 28-year-old holed from almost 40 feet at the 14th for a fourth birdie before making it five in a row from just off the 15th green.
That superb run, which took Fitzpatrick to ten under par, was halted by back-to-back bogeys at the 16th and 17th before he made his first par of the day on the 18th.
He drained another monster birdie putt at the short fourth before briefly returning to ten under with a birdie at the fifth.
But bogeys at the seventh and eighth meant he had to settle for a 69.
Reflecting on his day, Fitzpatrick said: "Pretty inconsistent really. I've played some really good stuff.
"Started off, came back from the delay, played really well on my front nine, starting on ten this morning.
"Sloppy mistakes, which was obviously disappointing, but plenty of birdies which was always a positive.
"Going into the weekend, the position I'm in, I'm very happy."
Frenchman Julien Quesne had a day to remember as he made a hole-in-one at the short fourth from 187 yards with a nine iron.
Home favourite Filippo Celli made the cut in his first tournament as a professional, adding a 72 to his opening 69 to head into the weekend on one under.