Murray brothers, Andy and Jamie lost in three sets to Raven Klaasen and Michael Venus in the quarter-finals of the Washington Open.
The British pair took the first set on a tie-break but lost a second as all 24 games followed serve.
Andy Murray is playing his fourth event since hip surgery in January.
Murray who is the former world number one feared his career might be over before having the hip resurfacing operation.
But he later returned to the doubles court five months later when he won the Queen’s title alongside Spain’s Feliciano Lopez.