John Isner beaten in Davis Cup tie in Switzerland . John Isner wins in four sets as Switzerland take 2 -0 lead . Mardy Fish saw off Stanislav Wawrinka in earlier match . Holders United States leading United States 2 -0 in Oviedo .
Roger Federer beaten in Davis Cup tie in Switzerland . John Isner wins in four sets as United States take 2-0 lead . Mardy Fish saw off Stanislav Wawrinka in earlier match . Holders Spain leading Kazakhstan 2-0 in Oviedo .