Murray left down and out by Cilic

Grand Slam dream left in ruins after world No 2 is outgunned by 6ft 6in Croat

A Grand Slam year that had promised so much for Andy Murray ended in the most disappointing result of his career here last night when he was comprehensively outplayed in the fourth round of the US Open. Having been considered for so long as one of the game's best young talents, the 22-year-old Scot discovered what it is like to be upstaged by one of the next generation when he was beaten 7-5, 6-2, 6-2 by Marin Cilic, who at 20 was the youngest player in the last 16.

Murray admitted that he had been troubled for the last week by an injury to his left wrist but refused to blame it for his display. "I just struggled today," he said. "I played poorly."

It was Murray's most dispiriting performance at his favourite tournament. The world No 2, who won the junior title here in 2004, loves playing at Flushing Meadows and his achievement in reaching the final here last year set him on a run of success which brought seven titles in the next 12 months.

Winning a Grand Slam tournament, however, is what Murray wants more than anything and for the fourth major in succession he was beaten by a lower-ranked opponent who raised his game on the big occasion. Cilic followed the example of Fernando Verdasco in the fourth round of the Australian Open, Fernando Gonzalez in the quarter-finals in Paris and Andy Roddick in the semi-finals at Wimbledon.

Murray either matched or bettered his previous results at those three previous Grand Slam tournaments, but if that was evidence of a steady rate of progression the run was rudely halted by Cilic, a 6ft 6in Croat long regarded as one of the best up-and-coming players.

Nevertheless Murray had beaten him in all three of their previous matches and the world No 17 had arrived here having won only one match on the US hard-court circuit.

The major difference between Murray's performance and his previous Grand Slam defeats was the fact that he played poorly for most of the match. His serve did little damage and his returns were well below his usual high standards. In his previous match against Taylor Dent, who has served faster than anybody here, he had returned superbly.

Above all there was a flatness about Murray's game. Although he had felt a lack of energy in his second-round victory over Paul Capdeville, that had lasted only for a set. Here, even when he had looked in little trouble in the early games, there was a lack of zip about his play. He has experienced dips in matches in the past but has nearly always found a way to turn things around.

"I returned poorly and he served well and that was really the difference," Murray said. "I didn't find a way to get myself into the match. There were very few long rallies after the first set and normally I'm able to get myself into rallies. On the return every time I had a chance he would hit a big serve or I would hit a poor return, especially on the second serve. I just allowed him to dictate the play a lot."

Murray agreed it was the biggest disappointment of his career but added: "I believe that I'll come back better and stronger from it. I'll learn a lot from what happened this week."

Declining to go into detail about his wrist problem, Murray said he still planned to play in Britain's Davis Cup tie against Poland in Liverpool starting next Friday. However, Murray's form dipped sharply after he seemed to aggravate the injury when slipping towards the end of the first set and John Lloyd, Britain's Davis Cup captain, will surely be concerned.

There had been little hint of the problems to come as Murray dropped only one point in his first three service games. At 2-3 Cilic saved two break points and at 4-5 he saved two set points with an ace and a big backhand.

Murray played a poor game at 5-5, dropping his serve to 15 after two forehand errors and a double fault. In the next game Cilic created set point with an ace and converted it when Murray put a soft backhand into the net.

Having mishit frequently in the early stages, Cilic started to strike the ball much more cleanly. He also served well, though Murray never found a rhythm on his returns and looked uncharacteristically sluggish. The Scot hit just 13 winners to Cilic's 35 and five aces to the Croat's 10.

Murray dropped serve immediately in the second set from 40-15 up and again two games later. At 4-0 up Cilic had won seven games in a row. At 5-2 Murray had three break points but Cilic held firm and took the set with two successive aces. Service breaks in the first and seventh games of the third set completed Murray's misery and sent Cilic into a quarter-final against Juan Martin del Potro, a straight-sets winner over Juan Carlos Ferrero.