The Norwegian, who took part in a cross-country competition just two days earlier, held off the challenge of Germany's Frank Luck who took silver at Soldier Hollow.
Victor Maigourov of Russia finished in the bronze medal position.
Late call-up Jason Sklenar led Britain's standings with a finish of 48th out of 87 competitors.
Mike Dixon and Mark Gee struggled into 79th and 81st places respectively.
Bjoerndalen put skiing power ahead of marksmanship to triumph.
The 28-year-old won the individual 10km sprint four years ago at Nagano.
This time, he missed two of his 20 targets to earn a two-minute penalty, yet still came home ahead of Luck in 51 minutes 03.3 seconds.
The winner had to recover from the 30km cross-country on Saturday, when he finished sixth.
Luck avoided any time penalty points with accurate shooting, but could could not do enough to overcome Bjoerndalen.
Reigning champion Halvard Hanevold, Bjoerndalen's team-mate, finished fifth, despite also not missing a single target.