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June 9 (Reuters) - A goal from Angel Di Maria earned Argentina a comfortable 1-0 win over Ecuador in a pre-Copa America friendly in Chicago on Sunday.

Di Maria, who will retire from international duty after the Copa America, gave Argentina the lead five minutes before the break after a through ball from Cristian Romero. However, they were unable to extend their advantage in the second half.

"It was a deserved win. We have to keep working as we always do and stay as united," Di Maria said after the game.

"Ecuador are an opponent we could meet in the Copa. We know it's going to be a very difficult tournament. Today was a good game to show what we can do."

Argentina take on Guatemala in another friendly on Friday before the defending champions kick off their Copa America campaign against Canada on June 20. They then play Chile five days later and Peru on June 29.

Ecuador face Bolivia on Wednesday and Honduras on Sunday as part of their preparations for the Copa America. They begin their campaign in the quadrennial tournament against Venezuela on June 22 before taking on Jamaica four days later and Mexico on June 30.

The Copa America will be held in the United States from June 20-July 14. (Reporting by Angelica Medina in Mexico City; Editing by Peter Rutherford )