Stark's babes battled back valiantly against the highly-rated visitors after losing an early goal here last night.
A close-range Gary Mackay-Steven strike cancelled out Alessandro Florenzi's headed opener midway through the first half.
The Azzurri went back in front at the start of the second half when Ciro Immobile slotted home after a defensive mix-up at the back.
And Lorenzo Insigne and substitute Samuele Longo added the finishing touches to the result with late goals for the Italians.
However, the home team's chances were seriously undermined by an injury to Rangers goalkeeper Grant Adam at the start of the second half. The big stopper, on loan at Airdrie United this season, was stretched off with his neck in a brace after suffering a head knock with his first touch of the ball.
Fortunately, the brother of Liverpool star Charlie, had only suffered a cut face and he was later given the all-clear by Scotland medical staff.
But Stark was forced to field Matthew Edwards of Rochdale as his replacement as Mark Ridgers of Hearts, who had performed superbly well in the first 45 minutes, had already been substituted.
Try as he might, Edwards looked hopelessly out of his depth at Under-21 level and was helpless to prevent the Italians romping to a comfortable triumph in the friendly international.
However, Stark, whose team has a massive European Championship qualifier against Bulgaria next month and high hopes of qualifying for Israel, believes the workout was invaluable for his side.
He said: "It was a big, big game for our boys. Whenever you play Italy it is a valuable experience. They are a country who have won World Cups and European Championships. They have also got a terrific pedigree at Under-21 level.
"It was as big a test as the boys could have hoped for. For our group of players, it was a good opportunity to test ourselves.
"We showed for long spells, in the first half in particular, that we could handle playing against Italy. We gave as good as we got. That augurs well for us in the other games.
"It was disappointing to lose goals in the way that we did, but it was worthwhile giving so many players game time against such good quality opposition."
Stark took the opportunity to make several replacements and handed a debut to Chelsea kid Islam Feruz who, aged 16 years and 228 days, beat Christian Dailly's mark to become the youngest ever Under-21 cap,.
Also featuring were Rhys McCabe, the young Rangers central midfielder who has made such an impact this season, and Dylan McGeouch of Celtic and Kenny McLean of St Mirren.
STARK said: "I have known about Rhys for a long time. I have watched him in a lot of youth games. He is a very versatile player. I have seen him at right-back, wide right and centre-forward.
"He has shown he can come into the Rangers first team and handle himself very well in the adverse circumstances that they are experiencing. The Italy game allowed us the opportunity to take him into the group and have a look at him.
"Dylan also has a bright future and has benefited from playing for the Celtic first team this season. He is a confident boy, confident in a good way, and likes to take on players and beat them."
Scotland: Ridgers (Adam 46, Edwards 52), Jack (Toshney 80), Wilson, Perry, Hanlon (Shinnie 80), Wotherspoon (Palmer 77), Kelly (McGeouch 46), Allan (McLean 61), Mackay-Steven (Armstrong 76), MacDonald (Feruz 61), Russell (McCabe 46).