RIGA, Latvia (AP) — Colin Blackwell and Conor Garland scored two goals apiece Thursday, and the United States beat Slovakia 6-1 to advance to the semifinal showdown with Canada in hockey’s world championship. The Canadians, who lost their first three games in the tournament, defeated Russia 2-1 on an overtime goal by Andrew Mangiapane. The other semifinal Saturday will pair defending champion Finland and Germany, which upset Switzerland 3-2 in a shootout. Finland defeated the Czech Republic 1-0. All four winners played preliminary round games in Group B and faced each other.