Alessandro Florenzi netted with a header after eight minutes and Mark Ridgers made three fine saves from Ciro Immobile either side of Gary Mackay-Steven hitting a post for Scotland.
Mackay-Steven levelled after 33 minutes, but Immobile restored Italy's advantage after Grant Adam, a half-time replacement for Ridgers, was taken off on a stretcher as a precaution seconds after the restart after taking a blow to the head.
Chelsea forward Islam Feruz, aged 16 years and 197 days, became Scotland's youngest under-21 international as one of seven debutants, but had a limited impact before the hosts went further behind to Lorenzo Insigne's (pictured) 76th-minute free-kick and Samuele Longo's 90th-minute strike.
The performances of Mackay-Steven and his Dundee United team-mate Johnny Russell, who played the first 45 minutes, were enough to warm Scotland boss Craig Levein on a cold night in the capital.
But the visitors' class told as Billy Stark's side were beaten in a match which provided important preparation for next month's European Championships qualification clash with Bulgaria.
Italy have a 100% record from their five qualifying matches to date and should unbeaten Scotland squeeze out of Group 10, where they trail Holland by one point with three matches remaining, they will be keen to avoid the Azzurri in the play-offs.
There was an impeccably observed minute's silence in memory of Piermario Morosini, who died of a heart attack during Livorno's Serie B fixture with Pescara earlier this month. Four of the Italy side which began this match were on the field that day for Pescara.
Scotland were behind from the visitors' first attack as Giuliuo Donati's right-wing cross found an unmarked Florenzi to head beyond Ridgers.
Ridgers reacted well to save with his feet from Immobile before Scotland's first strike on goal came after 22 minutes when Scott Allan, lightening the gloom in florescent orange boots, shot straight at Simone Colombi from 25 yards.
Ridgers spread himself well to save from Immobile twice either side of a left-footed Mackay-Steven shot which beat Colombi but hit the post.
An equaliser soon followed as Russell reacted to a ricochet off an Italian arm and made his way to the by-line before crossing for Mackay-Steven to tap in.
Russell forced Colombi into a save and Immobile volleyed over as the half ended level.
Adam was one of three half-time replacements, but his involvement lasted less than a minute as he was caught by Marco Crimi before departing after lengthy treatment.
Rochdale's Matthew Edwards became Scotland's third goalkeeper of the evening and his first task was to pick the ball out of the net as Immobile ghosted through the middle and tucked in.
The replacements continued, with Allan departing after 62 minutes for Feruz, who came to Glasgow from Somalia as an asylum seeker in 2001 before moving to Chelsea last summer. His introduction saw him beat the record held by Christian Dailly.
Edwards' goal was under continual pressure and Sansone hit the bar with an opportunist's strike from wide on the right.
A McCabe free-kick was repelled by Italy substitute goalkeeper Carlo Pinsoglio as Scotland attempted to respond before Insigne showed him how to do it at the other end, finding the top corner following a Ross Perry foul on the edge of the box.
Feruz found space for a shot which Pinsoglio parried wide before Scotland conceded a fourth when Longo netted.