The Austrian covered the Stelvio course in a two-run combined time of two minutes 50.41 seconds. He finished 0.25 seconds ahead of countryman Benjamin Raich. American Daron Rahlves, who led after the first leg, finished third, 0.68 seconds behind Maier.
Thomas Grandi of Banff, Alta., was fifth, while another Canadian, Ryan Semple of St-Fastin-Lac-Carre, Que., was 15th.
Jean-Philippe Roy of Ste-Flavie, Que., was third after the first run, but did not finish the second run.
Austria's Hermann Maier wold gold in the men's giant slalom Thursday in Bormio, Italy. (AP File Photo)
American Bode Miller ran into some problems on his first run. The winner of last week's downhill and super-G lost control on the steepest part of the course and crashed into an advertising banner.
Miller needed two stitches to close up a cut. The American was attempting to become the first man to sweep three gold medals at the worlds since Switzerland's Jean-Claude Killy won four in 1968. Miller still has two races left – Saturday's slalom and the new team event, which will conclude the championships on Sunday.
For Maier, Thursday's victory was sweet redemption after he finished fourth in the super-G that opened the championships and 17th in the downhill.
It was also his first gold medal at the world championships since he won the downhill and super-G titles in 1999.
"This is a very important victory for me, especially on this course which is very, very difficult," Maier said. "Daron was super on the first run and I knew he had six-tenths of a second, so I had to be very good on my second run."
Raich was seventh after the first leg, but posted the fastest time in the second run to claim the silver medal.
A strike on Wednesday by TV workers for Italian state broadcaster RAI forced the race to be postponed to Thursday.
