UFA, Russia — The United States advanced to the quarterfinals of the World Junior Hockey Championships Monday with a 9-3 win over Slovakia. The Americans' prospects of reaching the knockout round had looked dicey after losing to Canada a day earlier, but they dominated the Slovaks almost from the start. Cole Bardreau opened the scoring in the fourth minute but Slovakia's Matus Matis equalized just 14 second later. But the Americans gradually built up an insurmountable lead, helped by two goals apiece from Vince Trocheck and John Gaudreau. In Group A, the Czech Republic beat Switzerland 4-3 in overtime. — AP