The United States will contest the Confederations Cup final after causing a huge upset in Bloemfontein by inflicting a first defeat on Spain since 2006 with a 2-0 win.

Jozy Altidore and Clint Dempsey scored the goals as underdogs USA, having lost their opening two games in the tournament and only squeezed through Group B by the skin of their teeth, set up a final showdown against either Brazil or hosts South Africa on Sunday.

The result was one of the biggest shocks in recent international history, with the all-conquering Spanish having broken the record for consecutive wins with their 15th on the trot against South Africa at the weekend.

The European champions would also have claimed the record for the longest unbeaten run if they had avoided defeat, having drawn level with Brazil's run of 35 in that South Africa match.

Even the 86th-minute dismissal of Michael Bradley - son of coach Bob - could not deny the USA, who were left to celebrate a famous victory.

The US took a shock lead through Altidore in the 26th minute. Dempsey played the ball into his strike-partner on the edge of the box and the 19-year-old was allowed to turn Villarreal team-mate Joan Capdevila far too easily before firing in a shot that Casillas got his hand to but could not keep out.

Spain could not find the breakthrough in the second half, and their hopes of reaching the final were crushed when the US netted their second goal in the 74th minute.

Donovan's low cross should really have been cleared by Ramos at the far post, but Dempsey showed quick reactions to prod the ball away from the Real Madrid defender and past Casillas.

Spain got a brief glimmer of hope when Bradley was shown a red card for a heavy challenge on Alonso, but Del Bosque's side could not take advantage as the slumped to their first loss since going down 1-0 at home to Romania in a friendly in November, 2006.