Duncan Weir's last-gasp drop goal earned Scotland a 21-20 victory from a Rome contest between teams desperate to avoid the RBS 6 Nations wooden spoon.
Tries from Tommy Allan and Joshua Furno looked to have put Italy on course for their first victory in this season's tournament.
But in a much improved display from under-fire head coach Scott Johnson's team, Scotland grabbed their first tries of the Championship with Alex Dunbar's impressive double before Weir heroically nailed a 40-yard kick with just 10 seconds left to win the match.
The Scots had touched down in the Italian capital in desperate need of a win after the devastating 20-0 defeat to England a fortnight ago.
Johnson pinned his hopes on bite being added to his toothless pack in the returning Richie Gray - dropped for the Auld Enemy encounter after Johnson claimed the Castres lock needed to work on his defensive game.
But it was Dunbar who stepped up to the mark as he drove home twice in the second half to finally give the suffering Scottish support some cheer.
And Weir's late dramatics were reward for the coach's faith in the Glasgow fly-half after timid displays against Ireland and then England.
There was a familiar face lining up against the Scots as former Scotland Under-20 fly-half Allan started for the Azzurri, representing the nation of his Italian mother.
There were also record-breaking run-outs for skipper Sergio Parisse and prop Martin Castrogiovanni as they both earned their 104th caps, eclipsing the previous highest Italian tally set by Andrea Lo Cicero.
The Scots showed a hunger to attack in the opening stages but they got lucky after 13 minutes when Allan knocked the ball on just as he was about to finish off the home side's first real attack.
But the Perpignan back was still able to put his side ahead as he successfully kicked a penalty awarded for an earlier infringement.
After two hours of action across three matches without registering a point, Greig Laidlaw put Scotland on the scoreboard as he tucked away a penalty of his own.
From the same position as his earlier miss, Allan made amends as he stuck the ball firmly between the posts to edge Italy three points in front as Scotland began to lose their discipline.
The Dark Blues tried to be positive but their decision-making early on was once again their weak point, as the ball was handed back to the hosts just as anything meaningful was brewing.
The opposite was true of Italy as they opened Scotland up before Allan crashed through two weak tackles to score his second try for Italy, before converting his own touchdown for the extras.
Despite that setback, Scotland made a confident start to the second period, trimming the Italians back by three points as Laidlaw fired over a 35-yard penalty.
They wasted a chance to cut the deficit further when Laidlaw opted against kicking an easy penalty in favour of a surprise tap-and-go, only to see Matt Scott slip just as he played in the centre.
But then, after 54 minutes, the visitors' long wait for their first try of the tournament was ended.
From a ruck, Scotland worked the ball through Scott, then Stuart Hogg and finally Dunbar who drove between two Italians before careering over in the corner.
They still trailed, as Laidlaw failed with his conversion attempt from wide on the right.
But in the 68th minute that changed as Dunbar scored his second try. Sean Lamont burst past Allan before passing over to replacement scrum-half Chris Cusiter who shunted on for Dunbar to sprint home from 25 yards out, ignoring support runner Scott.
Weir took over the kicking duties with Laidlaw off and added the extra two to put Scotland on the verge of victory.
But their carelessness looked like it had come back to haunt them as they failed to cover their left flank, allowing Parisse to play in lock Furno to level before Luciano Orquera restored Italy's lead with the conversion.
With the clocking ticking down, however, Weir stepped up to the mark, sending his last-gasp drop goal over to hand Johnson's men a long-awaited win.