I'm obviously very disappointed: Murray

Five titles this year and a rise to number two in the rankings counted for nothing on Tuesday as Andy Murray's hopes of a first grand slam title were shot down by Marin Cilic in the fourth round of the US Open.

Murray appeared in control as he held two set points with Cilic serving at 4-5 down in the first set but the man charged with ending Britain's interminable wait for a grand slam champion failed to convert either and he spiralled to a 7-5, 6-2, 6-2 defeat he described as the most disappointing of his career.

To make matters worse for the 22-year-old he ended the match with discomfort in his left wrist, although he admitted his emphatic defeat had simply come about because his often magical game had not been up to scratch.

"I had a problem with (the wrist) for a week or so," the right-hander, who reached the final last year against Roger Federer and was widely tipped to go one better this time, told reporters.

"But regardless, I just struggled today. I played poorly. I'm obviously very disappointed.

"After the way that the last three slams went I felt like I had actually played well and lost. Today, it didn't feel like that. I had my chance in the first set and then struggled."

Sixteenth seed Cilic, yet another physically imposing player from Croatia blessed with a bullet serve, stayed with Murray in the first set before taking control after surviving his one tricky moment in the 10th game.

As Murray retreated into his shell, the 20-year-old Cilic steamed into a 4-0 lead in the second set.

There was no escape, nor hiding place for Murray as his inspired opponent never flinched in closing out the biggest win of his career.

Throughout the entire three sets Murray managed just three winners from the baseline -- a statistic that summed up the subdued nature of the Scot's tennis.

"Sometimes in individual sports that can happen. That's the tough thing about it. You don't have any other players or anyone to sort of hide behind and can sort of cover for you," Murray said. "You have to take responsibility yourself.

"I think one of the things about me that I've been very good at the last couple of years is finding ways to get back into the matches mentally. But today I could have been better in pretty much every part of the game."

While Murray goes home to check out his wrist, Cilic will face Argentina's Juan Martin del Potro for a place in the semi-final.

Both are younger than Murray and both appear equally capable of challenging Federer, Rafael Nadal and Novak Djokovic for major silverware.

Winning his first slam will not, it seems, be getting easier for Murray any time soon, although he remains upbeat.

"I think next year I've got a very, very good chance of doing it. I think I'll be a better player next year."