ST. MORITZ, Switzerland (AP) — World bobsled champion Kaillie Humphries of Canada defended her title Saturday, extending an overnight lead in the final two runs. Elana Meyers of the United States took silver.

Humphries, the Olympic champion, and brakewoman Chelsea Valois were 0.68 seconds faster than Meyers and Katie Eberling, who had been third after the first two runs Friday.

The Americans had a 0.02 edge over German bronze medalists Sandra Kiriasis, the 2006 Olympic champion, and Franziska Bertels.

Kiriasis reached the fastest speed of the competition (90 mph), but superior driving by Humphries won in a combined four-run time of 4 minutes, 30.31 seconds.

"Four consistently good runs are what won us gold," said Humphries, the favorite to repeat her Olympic victory next year. "Now Sochi is my next goal."

Earlier, junior world champion Francesco Friedrich of Germany led the two-man competition. Defending champion Steven Holcomb of the U.S. is third.

The 22-year-old Friedrich and brakeman Jannis Baecker hold a 0.35-second advantage over World Cup champion Beat Hefti and Thomas Lamparter of Switzerland. Friedrich had a combined two-run time of 2 minutes, 11.10 seconds.

Holcomb and Steven Langton have 0.77 seconds to make up in the final two runs scheduled Sunday.