Under stunning blue skies at the Laura Cross-Country Ski Centre, Bjørgen known back home as ‘Gull-Marit’ (‘Golden Marit’) put in a storming performance to finish ahead of Sweden's Charlotte Kalla. Heidi Weng of Norway took the bronze to complete an all-Scandinavian podium.
The skiathlon - also known as the 15km pursuit and the combined 7.5 + 7.5km mass - start is a combination of 7.5 km classic style immediately followed by 7.5 km freestyle skating, which requires competitors to display a full repertoire of technique, speed and stamina.
Bjørgen, 33, arrived in Sochi in dazzling form, having recently extended her record tally of World Cup wins to 64. She now has a total of eight Olympic medals (four gold, three silver, one bronze), including five won at Vancouver 2010, more than any other athlete.
Wearing the No 2 bib, the 12-time world champion quickly set the pace. First at the 3.75km mark (9:42.0), and again at 5.4km (13:57.6) she maintained the lead going into the halfway mark and the changeover.
However, following a sluggish change going into the freestyle, the reigning champion found herself down to 26th, and had to claw her way back through the pack thanks to a strong burst of pace at the 11km mark.
Leading the way for most of the second half of the race was another Norwegian, Therese Johaug, before a surprise attack from Kalla in the last kilometre.
That sparked an instant reaction from Bjørgen, who had, until then, been content to hang on Johaug’s shoulder.
In a dramatic finish, the Norwegian ace overhauled her Swedish rival, who is the reigning Olympic 10km freestyle champion, to pip her to the line by one second and eight hundredths.
Meawhile Johaug, who currently leads this season’s World Cup rankings, was denied a place on the podium by her compatriot Heidi Weng, who finished 13 seconds and two hundredths off the pace to claim bronze. Four-time Olympic champion Justina Kowalczyk of Poland, one of the pre-race favourites, could only manage sixth place, almost a minute behind Bjørgen.
After crossing the finish line in first place the “Iron Lady” as Bjørgen is also known, collapsed in a mixture of joy and exhaustion.
“One gold was my goal, so now I can relax a little bit. I can enjoy the rest of the Games,” said the Norwegian, who will resume the medal quest on Tuesday 11 February with a defence of the women’s 1.5km freestyle sprint title.