An out-of-sorts Andy Murray lost in straight sets to Croatian teenager Borna Coric to crash out of the Dubai Duty Free Tennis Championships on Thursday.

Murray thrashed Coric in a Davis Cup singles tie in September 2013 in their only other previous meeting, but was second best throughout Thursday's quarter-final encounter as the 18-year-old Coric won 6-1 6-3 in one hour and 19 minutes.

Coric's reward for claiming the world number three's scalp is a semi-final match against Roger Federer, providing the Swiss world number two can successfully overcome Richard Gasquet later.

Murray's error-strewn display, in which he hit 55 unforced errors, was in stark contrast to the impressive tennis the Scot played on his way to the Australian Open final just three weeks ago.

The two-time grand slam winner began steadily enough, holding his serve to take a 1-0 lead, but found himself chasing the set in a matter of minutes as Coric, who beat Rafael Nadal at last year's Swiss Open, held with ease then converted a second break point against the Scot to move into a 2-1 advantage.

Coric did not drop a point as he held his second service game and extended his lead to 4-1 by converting his fourth break point as Murray struggled to get a foothold in the game.

Coric breezed through his third service game to make it 5-1 and broke Murray for a third time to win the first set after the Scot sliced a backhand ground stroke into the net to notch his 27th unforced error.

Murray matched his opponent in the early stages of the second set as it went with serve and drew on all his experience to level to 2-2 as Coric stepped up the pressure.

The Croatian, the youngest player in the men's top 100, was exhibiting skill and poise that belied his tender years and after breezing through yet another service game, he produced a fine lob to break Murray to take a 4-2 lead.

Coric was in total control by this point and held serve without dropping a point before wrapping up a thoroughly deserved victory moments later when Murray skewed a regulation forehand return wide of the mark.

Afterwards Murray praised world number 84 Coric's performance, admitting that his slow start to the match had ultimately cost him.

"He didn't make many errors," Murray told the ATP website. "He played very solid and he moved well.

"I made way too many mistakes from the beginning of the match right through to the end, early in rallies, rushing points."