Murray exit catches Del Potro off guard

Juan Martin del Potro spoke of his surprise that he would be facing Marin Cilic in the US Open quarter-finals and not world number two Andy Murray.

Britain's Murray, a finalist at Flushing Meadows 12 months ago, crashed out of the final grand slam of the year in a straight sets defeat to the Croatian 16th seed, describing it as the most disappointing loss of his career.

"Cilic has everything to be a good player," del Potro said. "But Murray is number two, winning everywhere."

Argentina's del Potro, meanwhile, cruised into the last eight with a 6-3 6-3 6-3 win over Spain's 24th seed Juan Carlos Ferrero, setting up a showdown with the 6ft 6ins Cilic, who will be making his first appearance in a grand slam quarter-final.

Murray will vouch for that as he failed to reach the levels of play that had earned him five ATP Tour titles in 2009, Cilic romping to 7-5 6-2 6-2 win at Arthur Ashe Stadium.

Asked if the defeat was the biggest disappointment of his career, Murray replied: "My tennis career, yes. I mean, worse things have happened to me, that's for sure.

"In terms of tennis I guess it's just kind of the way the match went that really makes it disappointing."