The Italian marksman shot an Olympic record of 1,180 points in qualification at the London Olympics men's 50-meter three-positions rifle, to lead the field by a massive eight points on Monday.
It looked like an insurmountable difference, and it was.
Campriani never got in trouble during the final ten shots and claimed the gold with 1278.5. It also set a new best mark at the Olympics, improving on the 1275.1 by Rajmond Debevec of Slovenia 12 years ago.
Kim Jung-Hyun of South Korea narrowed the gap with Campriani by two points to win silver, overtaking bronze medallist Matthew Emmons in the last of the final's ten shooting rounds after the American shot the lowest single-shot score of the final.
"You never know, especially in this event and what happened in the last two Olympics," said the Italian, referring to Emmons, who led in both the 2004 and 2008 finals but tearfully missed out on a medal both times.
In 2004, Emmons accidentally fired at the wrong person's target on his last attempt, earning no points. And four years later, his gun incidentally went off while he was still lining it up, causing a low score that saw him drop to fourth.
This time, Emmons was way off the mark with a 7.6 of a possible 10.9 on his final shot, dropping him from silver to bronze.
"Really today, it was just nerves," Emmons said. "This was one of the hardest matches I ever shot. I had the weight of millions of people on my back hoping that I would win."
Emmons qualified in second place for the final, but never had a shot at the gold because of Campriani's lead.
The American dropped from second to fourth, overtaken by Kim and France's Cyril Graff after three shots. But Emmons hit back, shooting five 10's in his next six attempt to go 1.6 clear. However, Kim reversed the order one more time.
It didn't matter to Emmons. A medal is a medal, especially after everything he has been through over the past four years.
He became a father ("That's the coolest thing ever, I love that.") and fought thyroid cancer.
"I dealt with all thing really well," Emmons said. "I performed the very best I could, given what I had."
So bronze instead of silver?
"Pfff, for me, any medal is good," Emmons said.
Emmons liked the medal — his first in the discipline though he won gold in Athens and silver in Beijing in the 50-meter rifle prone — but almost lost it again after the competition and the winner's ceremony.
Emmons wanted to throw his flowers in the audience — but nearly tossed his medal instead.
"I guess it didn't want to be there very long," Emmons said jokingly, pointing at the medal around his neck. "But it's there now, it's safe."
It was Campriani's second medal in London after he won silver in the 10-meter air rifle.
"In the final, eight points gap, everyone thought it was enough," Campriani said. "But it wasn't fun, it put me under extra pressure as I had everything to lose ... I had problems with my heartbeat but my timing was good."
After winning, he said he felt "great. After the silver medal, it was really hard to stay focussed on today."
Spending time with his girlfriend before the event helped him gather his strength, Campriani said.
Campriani announced a break from shooting to study sports engineering in Sheffield, England, before returning to the sport in 2013.