VIDEO: Portugal Goal: Nani Scores On USA Defense Mistake

After an improbable and fantastic start to the opening match against Ghana, the U.S. was on the wrong end of a defensive error against Portugal in the second game. A goal by Nani in the fifth minute put the Portuguese up in Manaus, 1-0.

Geoff Cameron, who was so effective in the U.S. match against Ghana, made one of the more brutal mistakes in U.S. World Cup history. On a routine clearance, the ball hit the center back's shin, and deflected to Nani. The Manchester United winger had no problem delivering a rising ball past goalkeeper Tim Howard to put Portugal ahead.

Entering the 2014 World Cup, Cameron was considered the most reliable defenders in a group of rather inexperienced defenders. Jurgen Klinsmann was expected to rely heavily on Cameron to anchor the middle of the defense.

Cameron, 28, plays for Stoke City in the English Premier League. He was a valuable defender for the club in the 2013-2014 season.

The lapse by Cameron is reminiscent of Jeff Agoos's mistake in 2002 against Portugal

The U.S. benefited from a defensive mistake in the opener. Ghana's John Boye made an awful effort in the opening minute against the Yanks by allowing Clint Dempsey to easily go around him and score a surprising goal along the left side.

USA vs Portugal 0-1 Nani Goal (World Cup 2014)by hdgoals11