Luis Palma and Michael Johnston added second-half goals for the Glasgow side while Christopher Nkunku averted a shutout for the London side with an 89th-minute penalty kick.
Celtic, which won 4-3 on Tuesday over English Premier League champion Manchester City, dominated the match at the University of Notre Dame in South Bend, Indiana.
Celtic seized the lead in the 19th minute on O'Riley's left-footed blast from the right side of the box inside the far post.
An unguarded Furuhashi tapped in a left-footed shot in the 33rd minute from point-blank range off a centering pass from O'Riley to give the Scottish side a 2-0 advantage at half-time.
Honduran striker Palma boosted the lead in the 76th minute and Johnston netted the Hoops' final goal in the 79th.
Later Saturday friendlies from top European sides at US venues include Manchester City against AC Milan at New York and Manchester United against Arsenal at Los Angeles.
