Mancuso became the US giant slalom champion when she was 16

The 22-year-old Olympic giant slalom champion clocked one minute, 38.93 seconds to beat Renate Goetschl into second by just 0.43 seconds.

Last year's winner, Lindsey Kildow, was third in a time of 1:39.47.

The race was delayed by 15 minutes after Italian Nadia Fanchini suffered a nasty crash during her run.

Fanchini crashed into the safety netting and was taken down the hill on a stretcher with pains in her knee and head.

The Italian Ski Federation said that she had suffered concussion.

"Nadia broke her wrist in two places and briefly lost consciousness," said a statement.

"She has been taken to Mouthiers hospital where she has had a scan which did not reveal any more problems."

Mancuso, who had three podium finishes last season, had surgery to correct a long-term hip problem in the off-season.

"I'm just coming back from that and it's been tough but I knew I had a pretty good run, it felt smooth," she said.

"It just seemed like everything lined up perfectly for me. I'm just starting to get the good feelings back all the time."

World Cup downhill result from Val-d'Isere:
1. Julia Mancuso (US) 1:38.93
2. Renate Goetschl (Aut) 1:39.36
3. Lindsey Kildow (US) 1:39.47
4. Anja Paerson (Swe) 1:39.58
5. Ingrid Jacquemod (Fr) 1:40.45
6. Alexandra Meissnitzer (Aut) 1:40.60
7. Kelly Vanderbeek (Can) 1:40.61
8. Lucia Recchia (It) 1:40.76
9. Dominique Gisin (Swi) 1:40.90
10. Andrea Fischbacher (Aut) 1:40.95

Downhill standings:
1. Kildow 240 pts
2. Goetschl 175
3. Maria Riesch (Ger) 132
4. Mancuso 126
5. Fischbacher 116
5. Paersonm 116

Overall World Cup standings:
1. Nicole Hosp (Aut) 421
2. Goetschl 391
3. Marlies Schild (Aut) 377
4. Kildow 335
5. Kathrin Zettel (Aut) 310