Michael Greis won the 20km biathlon to claim the first gold medal at the 2006 Winter Olympics in Turin.
Greis denied defending champion Bjoerndalen by 16 seconds
The German, 29, held off a late surge from Ole Einar Bjoerndalen to clinch victory in a time of 54:23 minutes.
Bjoerndalen, who won gold in 2002, finished 16 seconds behind while fellow Norwegian Halvard Hanevold pipped Russian Sergei Tchepikov for bronze.
British hope Tom Clemens had to settle for a finish of 57th out of 88 competitors on Saturday.
Greis, who leads the world standings in the 20km, matched a fast skiing display with an impressive shooting performance, missing just one of his 20 targets.
"It was a fantastic race," said Greis. "It worked out very well, it was really perfect.
"Over the last few days I've felt in really good shape. I've worked at the shooting range to get a better feel for my rifle.
"But I didn't wake up in the morning thinking I'd be Olympic champion. It's a dream come true.
Bjoerndalen, who swept the four biathlon golds in Salt Lake City and had designs on winning all five medals in Italy, missed a target in each of his first two shooting sessions.
Bjorndalen's 36-year-old team-mate Hanevold also provided a gripping conclusion for the bronze medal.
Tchepikov clocked a combined time of 55:32.7 before Hanevold edged him by just 0.8 seconds to claim the last podium place.
Army corporal Clemens was happy with his position of 57th on his Olympic debut.
He had flagged towards the end of the competition, where he missed four of his 16 targets, including two on the final loop.
"I'm happy with this. I skied well but I was just really tired coming in to shoot for the last time," he said.
"If you shoot slowly, the lactic builds up in your legs and makes them shake so I thought I just couldn't waste any more time and decided to shoot quickly."