Just three days after his glory on the gruelling Galibier, 30-year-old Visconti used a smaller climb as the platform for a third successive stage win for the Spanish Movistar team.
Visconti attacked the main pack on the punchy Cat.4 ascent of Crosara 20 kilometres from the finish of the otherwise largely pan-flat 218km stage from Caravaggio.
Having swept up Colombia's Miguel Angel Rubiano (Androni-Giocattoli) and fellow Italian Danilo Di Luca (Vini Fantini) on the steepest 12% section of the climb, Visconti crested the summit in pole position before riding with real gusto to hold off the chasing pack all the way to the finish.
It was Visconti's second stage win of the race following victory in Sunday's stage 15 - and his team's fourth after additional scalps for Spain's Benat Intxausti in Tuesday's stage 16 and Britain's Alex Dowsett in the opening week's individual time trial.
Lithuania's Ramunas Navardauskas crossed the line with arms aloft to take second place 19 seconds down on the winner, the Garmin-Sharp rider clearly believing he had notched his own second scalp of the race.
Maglia rosa Vincenzo Nibali (Astana) finished safely in the main pack to retain his race lead by 1:26 over Cadel Evans (BMC) and 2:46 over Rigoberto Uran (Team Sky) ahead of Thursday's decisive 20.6km uphill time trial.
Visconti's Movistar team started the stage on a role having picked up wins in the previous two stages either side of Monday's rest day.
But with the sun shining high in a blue sky, it was the Omega Pharma-Quick Step team of the red jersey Mark Cavendish who controlled the tempo of the stage as a break of four riders rode clear after just six kilometres of racing.
The only team with more success that Movistar in the 96th Giro d'Italia, OPQS clearly fancied delivering their man Cavendish to a fifth win of the race.
Russia's Maxim Belkov (Katusha) - himself a previous winner of last week's sodden stage nine to Florence - joined forces with the peloton's youngest rider, 22-year-old Australian Luke Durbridge (Orica-GreenEdge), the Belgian Gert Dockx (Lotto Belisol) and Rubiano to build up a maximum lead of five minutes over the peloton.
Leading the chase alongside OPQS was Movistar and the Argos Shimano team of Slovenian sprinter Luka Mezgec. With the quartet's lead cut to just one minute ahead of the only climb of the day, the bright yellow jerseys of Vini Fantini moved to the front of the pack as the roads became ever lumpier and narrower.
Belkov was first to pop and was quickly followed by both Dockx and Durbridge. Vini Fantini's Alessandro Proni then burst off the front as the pack hit the initial slopes of the Crosara, with 23km remaining. Proni's move acted as a springboard for Di Luca, who burst clear of the pack to join Rubiano 30 seconds up the road.
Meanwhile, Cavendish dug deep to stay in touch with the fast-slimming main pack on the steepest section of the climb. While Cavendish grimaced in pain off the back, the in-form Visconti made his move and danced off the front.
Powering up the slope as if it were a mere small incline, Visconti quickly caught the leading duo. Di Luca cracked one kilometre from the summit before Visconti rode ahead to cross over the peak with a 16-second lead over Rubiano and a 32-second advantage over the pack.
Once Rubiano was swept up on the descent the attacks came thick and fast - but there was no unified effort from the chasing group and Visconti, perhaps digging even deeper than he did on the Galibier three days earlier, managed to maintain a gap of just over 20 seconds.
With Spanish sprinter Francesco Ventoso present in the chasing group, Movistar had a second card to play should Visconti come up short.
The lone leader suffered a heart-in-mouth moment when overcooking a tight left-hand bend entering Vicenza with 2km remaining - but Visconti managed to readjust his line before continuing on his way to glory.
"It's an incredible feeling," Visconti said. "This was definitely a stage which suited both me or Ventoso and we had targeted it in the morning."
The chasing pack crossed the line 19 seconds down with Navardauskas, the stage 11 winner, edging out Mezgec for what he believed to be the victory. Behind the Lithuanian Ventoso could be seen celebrating his team-mates win as he coasted to a ninth-place finish ahead of Evans.
The Australian veteran took five points over the line and now moves to within four points of Cavendish in what is proving to be a thrilling battle for the red jersey.
Earlier in the day, Cavendish had taken maximum points for fifth place at both intermediate sprints behind the escapees to move 10 points clear of Evans.
One day after his 28th birthday, the British sprinter would also have hoped for a chance to contest both the final sprint and mop up more points in Vicenza - but despite his best efforts he lost touch on the Cat.4 climb and came home 1:39 down on Visconti.
"There are climbs that put the sprinters on the limit and there are GC climbs - and that was a GC climb," Cavendish told Eurosport after a disappointing day in the saddle.
"There's nothing we could have done more. We always knew it was going to be hard and it was. I cracked on the climb. The guys were excellent and stayed with me - but what can you do? I'm so proud of them. At the end of the day it doesn't always work out."
With two back-to-back days in the mountains following Thursday's 20km time trial, Cavendish will have to wait until the final flat stage into Brescia on Sunday to see if he can win the red jersey.
Last year Cavendish missed out on the jersey by one slender point - and with Evans sure to pick up points on Friday and Saturday it now looks very much an uphill struggle for the Manx Missile.
- Sports & Recreation
- Danilo Di Luca
- Mark Cavendish
- Miguel Angel Rubiano
- Cadel Evans