Ecuador assistant coach Luis Suarez rued the side's missed chances in the second half as it was eliminated from the Copa America Centenario at the hands of the United States. 

Clint Dempsey scored one and set up another as the host U.S. secured a 2-1 win at CenturyLink Field in Seattle on Thursday to move into the semifinals. 

Michael Arroyo scored with 16 minutes left to set up a tense finish after both sides had been reduced to 10 men, with Antonio Valencia and Jermaine Jones seeing red. 

Enner Valencia had two gilt-edged chances to find an equalizer, while Brad Guzan produced a stunning save in second-half stoppage time to deny a certain own goal. 

Ecuador coach Gustavo Quinteros was sent to the stands in the dying stages after protesting a refereeing decision, with Suarez forced to front the media after the game in his absence. 

"There were two games. One in the first half that was dominated a bit by United States, and the second that was totally all Ecuador," the 47-year-old said. "But all that was lacking in the end was that conviction and forcefulness. 

"If we count the chances of both teams, USA had three and they scored two. We had five chances and could only score one."

He added: "We did everything we could to be celebrating right now, but instead it fell to the United States. We have a clear conscience."