Former US Olympic 100m sprinter Lauryn Williams marked her debut as a winter Olympian on Tuesday by topping the opening heats of the women's bobsleigh in Sochi. Williams, a silver medallist at the 2004 Athens Olympics and part of the 2012 gold-medal relay squad in London, was the brakewoman on USA-1, piloted by Elana Meyers. Meyers, who won a bronze medal at the 2010 Vancouver Games, performed two consistent runs to clock a combined time of 1min 54.89sec for two runs and finish 0.23sec ahead of reigning champions Kaillie Humphries and Heather Moyse of Canada. In her first run, two-time world champion Meyers set a new track record with a time of 57.26sec. The USA-2 team of pilot Jamie Greubel and brakewoman Aja Evans sit third with a time of 1min 55.45sec. The medal winners will be decided after the third and fourth runs on Wednesday. The times of all four runs are added together to determine the winner. Source: AFP