The Norwegian, who heads the overall World Cup standings from defending champion Marcel Hirscher, was second behind American Steven Nyman in Friday's downhill at the Saslong course in Northern Italy on Saturday.
But the reigning Olympic champion in the super G responded in the ideal manner as he powered to his fourth World Cup victory of the season and seventh in his career.
Jansrud clocked a time of one minute and 33.87 seconds, finishing 0.46secs ahead of home hope Dominik Paris, who recorded his second straight podium after claiming third in the downhill.
Paris' compatriot Christof Innerhofer rounded off the top five behind the Austrian pairing of Hannes Reichelt and Vincent Kriechmayer.
While his Austrian countrymen enjoyed a strong day, Olympic downhill gold medallist Matthias Mayer was unable to finish his run, a failure matched by Nyman and fellow American Ted Ligety.
With many of the expected big challengers struggling to live up to the expectations, Jansrud now leads the overall standings by 152 points, with Paris staying in third behind Hirscher.
Jansrud also sits atop the downhill and super G tables, although his lead in the overall rankings could soon diminish with Hirscher set to contest in the upcoming giant slalom and slalom races in Alta Badia and Madonna di Campiglio on Sunday and Monday.