Britain's Aljaz Bedene was knocked out in the US Open second round after he lost in four sets to American Donald Young.
Slovenia-born Bedene, who switched allegiance to Britain in March, is yet to go past round two of a major tournament and the world number 57's wait continues after Young progressed 3-6 6-4 6-4 6-2.
It marks a disappointing end for Bedene, who had reached this stage with an upset win over Latvia's Ernests Gulbis.
He had also beaten Young in their only previous meeting three years ago and sits 11 places above his opponent in the ATP world rankings.
Bedene started well, opening up a break point in the fifth game and then converting a second chance to lead 4-3 when a Young forehand flew long.
Serving out the first set with ease, the British number two then broke at the first opportunity in the second to lead 2-0 but thereafter it was Young who went on the charge.
Breaking back immediately, the American tightened up from the baseline and one more break allowed him to clinch the set and level the match.
Bedene had been the more consistent in the early stages but suddenly it was his groundshots that began to go astray while his wobbling first serve offered Young further room for encouragement.
The momentum had firmly shifted as Young broke twice in the third set and twice more in the fourth to seal a convincing victory in two hours and 42 minutes.
Young will now face Serbian Viktor Troicki in round three.
Source: PA
