Biathlete Bjoerndalen claimed a record-equalling 12th Winter Olympic medal by winning the men's 10km sprint at the Laura Biathlon Center above Rosa Khutor.
Bjoerndalen, who celebrated his 40th birthday last month, matched the total mark set by his compatriot, former cross country skier Bjoern Daehlie.
In holding off Austrian silver medallist Dominik Langertinger by less than a second, Bjoerndalen also claimed the eighth Olympic gold medal of his career.
Bjoerndalen said: ''I think this is one of my most important victories. When I missed a target on the last loop I thought I had no chance to win, but I believed I could make the podium if I continued with my speed."
Bjoergen's quest to win six medals, meanwhile, began with victory in the women's cross country skiathlon.
Bjoergen, who won five medals in Vancouver four years ago, also has designs on eclipsing the medal record held by her compatriots.
And that challenge began in superb fashion with the successful defence of her 7.5km + 7.5km skiathlon title at the dramatic Laura Endurance Center.
Bjoergen, 33, completed the gruelling race in 38 minutes 33.6 seconds to finish 1.8 secs ahead of Sweden's Charlotte Kalla.
Norway finished with three racers in the top four, with Heidi Weng (38:46.8) claiming the final podium spot ahead of Therese Johaug.
The Scandinavian nation also secured silver in the inaugural snowboard slopestyle event, which was won by Sage Kotsenburg of the United States - the first gold medal of the Games.
A nigh-flawless first run saw Kotsenburg register a score of 93.50, and that proved too tough to beat for his fellow competitors, with Norway's Staale Sandbech winning silver and pre-tournament favourite Mark McMorris of Canada bronze.
Holland also enjoyed a flying start to the Games with a one-two-three placing in the men's 5000 metre speed skating.
Sven Kramer broke his own Olympic record to retain his title, taking gold in six minutes 10.76 seconds and beating the time he set in Vancouver four years ago by almost four seconds.
The 27-year-old finished 4.95 seconds clear of compatriot Jan Blokhuijsen, while Jorrit Bergsma rounded off a perfect display from the Dutch trio.