Sara Hector went out first in Copper Mountain, Colorado, and had a nearly flawless first run.
Only New Zealander Alice Robinson was faster in the first run, 29 hundredths of a second ahead of Hector.
Julia Scheib, Austria, is third, six tenths behind.
Sara Hector finished ninth at the giant slalom premiere in Sölden at the end of October and is now chasing her eighth World Cup victory of her career.
Last season, Sara Hector took two victories in giant slalom and had two more podium finishes. She also took two podium finishes in slalom.
Two more Swedes will be allowed to run the second run. Estelle Alphand came in 29th place, 2.5 seconds behind Robinson, and Hanna Aronsson Elfman had a 30th time, 2.61 behind.
The second run starts at 9:30 PM.
