The 30-year-old needed to produce a fast time on his second slalom run to push shock leader Bode Miller of the United States off the top spot.
And he did so, but only by 0.28 seconds, to win his sixth Olympic medal.
Aamodt's amazing Olympic record
Giant slalom - bronze; Super-G - gold
Downhill - silver; Super-G - bronze; Combined - silver
Combined - gold
The bronze went to Benjamin Raich of Austria, while Great Britain's Ross Green surprised many by finishing 15th.
"I'm delighted with the way things went. It was a good time to put my best ever slalom run together," said the Briton.
It was arguably Aamodt's downhill section of the combined event that won him the gold.
The 30-year-old's time of one minute 38.79 seconds was 0.2 faster than compatriot Lasse Kjus, enough to take the lead.
Aamodt, who is renowned for his slalom skills rather than downhill, could now only throw the title away.
It seemed as if his closest challenge would come from the Austrians Raich and Rainer Schoenfelder.
But to everyone's surprise it was the 24-year-old Miller, 15th after the downhill, who set the course alight by taking the outright lead after his two slalom runs.
Kjus was unable to cope with the pressure and dropped down to fifth after his runs, so it was left to Aamodt to win the day for Norway.
And although the 30-year-old was almost two seconds slower than Miller on his final run, the advantage he had gained in the downhill eventually proved to be crucial.
"I have been skiing combined well all year. I knew Bode would be dangerous. I was lucky he had so many mistakes," said Aamodt, whose sixth Olympic medal is a record for an alpine skier.
"I also skied more careful because I had a big lead. I was happy it was enough to win."