The United States rink of John Shuster and Cory Christensen improved to 6-0 at the World Mixed Doubles Championship with an 8-5 win over previously undefeated Spain on Wednesday at Stavanger, Norway.

The Duluth Curling Club duo stands alone atop Group F with one remaining match Thursday against Russia (5-1) at Sormarka Arena.

The Americans scored three points in the first end against Spain's Oihane Otaegi and Mikel Unanue and put the match away with four points in the sixth end.

• The U.S. women, including Silver Bay's Norma O'Leary, qualified for the playoffs at the World Senior Championships with a 9-4 victory over winless Lithuania on Wednesday at Stavanger.

Margie Smith's rink improved to 5-1 in Group A (second behind Canada) with one round-robin match left against Canada on Thursday.