A total of 98,000 fans at Tuscany's positively throbbing Mugello circuit were left ecstatic with the Italian rider's win.
Battling to overcome a stomach bug, Dovizioso held his nerve in a breathless race to take his first ever victory at the circuit, and Ducati's first there since Casey Stoner's victory in 2009.
Italian celebrations were made even sweeter when Danilo Petrucci, riding for Ducati satellite team Octo Pramac Ducati, managed an unlikely third place.
Spain's Maverick Vinales reinforced his championship lead with a strong second position on his Movistar Yamaha, pursuing Dovizioso until the final corner while Valentino Rossi, recovering from a recent Motocross accident that had threatened his participation, came in fourth.
Dovizioso's race could have easily ended with 21 laps to go. Cresting the hill on the Mugello straight his bike's fearsome power almost got away from him, both wheels writhing violently on the tarmac as the rider grappled to decelerate from 220 mph to the 50 mph needed to safely negotiate the corner. In a heart-stopping moment the Italian left the saddle but somehow managed to regain control.
Mugello is Rossi country, but an Italian winning on an Italian bike perhaps trumped even the joy of a win for the fans' favorite. The popular Ducati rider crossed the line to a ferocious roar from the crowd.
It was a bad day at the office for Repsol Honda, with reigning world champion Marc Marquez nursing his bike into sixth place -- points that may be crucial at the end of the season -- while his teammate Dani Pedrosa lost the front end of his bike, sweeping both him and LCR Honda rider Cal Crutchlow into the gravel.
Jorge Lorenzo also faded after a strong start on his Ducati, with grip issues pushing him back to eighth.
A champion remembered
The day also saw a touching moment at the start of proceedings. There was a ceremony to remember Nicky Hayden, who died last month
after injuries sustained in a cycling accident.
The entire grid paused in an impeccably observed silence for 69 seconds -- 69 was the American's race number -- and riders including Rossi incorporated the number into their race liveries.
Dovizioso shrugged off his pre-race illness, which even saw him sit out the morning warm-up.
"When the light switched off, I felt good, not with a special energy, but enough to make the right things in the right moments," he told reporters.
He also admitted he was unaware of Vinales' Yamaha stalking him at the end. "Until the last brake I couldn't know if Maverick was there, I couldn't hear, so I didn't know, so I braked quite inside, but when I opened the throttle on exit, I say nobody can overtake me. I won, I win, I won, I won!"
At the podium ceremony, the crowd erupted, chanting Dovizioso's name as he accepted his winner's trophy to the strains of Fratelli d'Italia.
This was Ducati's and Italy's day.