Engineering student Campriani won silver in the 10m Air Rifle earlier in the Games and went one better on the final day of competition at The Royal Artillery Barracks.
The destination of the gold was never in doubt after Campriani started the final with an eight-point lead having smashed the Olympic record in qualifying with a score of 1180 - and he finished six points clear with a combined Olympic best.
But there was drama behind him, USA's Matt Emmons lying second with a 1.6-point lead with one round to go.
But he produced the worst shot of the final, a 7.6, allowing Republic of Korea's Kim Jonghyun to snatch silver with a 10.4.
Emmons took bronze, with Cyril Graff of France just 0.3 behind.
'It's never over until it's over,' Emmons said. 'Anytime you can be on the podium at the Olympics is a pretty cool thing. After the last shot I looked down and thought "hey, I got bronze, cool".'
'If I'm nervous and make a mistake then I make a mistake, and that's what happened,' he said.
It's not how you win but how you handle the loss that makes you a champion.Niccolo Campriani
Campriani, who was the first athlete from any sport to qualify for London 2012 when he won a World Cup event two years earlier, said: 'It's not how you win but how you handle the loss that makes you a champion.
'Matt is incredible, in Beijing he was smiling after 10 minutes, it was the most amazing thing I have ever seen on a shooting range.
'He's an inspiration to me and a great champion.'