The New Saints went down 3-0 to CSKA Sofia and now face a mountain to climb in the second leg after conceding three late goals in their Europa League play-off first leg in the Vasil Levski National Stadium.
The Welsh champions had put in a great performance to frustrate their Bulgarian hosts for 81 minutes before being hit by a double whammy.
A Boris Galchev free-kick was headed into the far corner by Guiseppe Aquaro and, within a minute, sub Gregory Nelson added a second.
And, in the final minute of normal time, CSKA probably put the tie beyond the Saints when Spas Delev, the player at the centre of an ineligibility row earlier in the week, took the ball across the edge of the box before firing a superb shot beyond keeper Paul Harrison.
There had been little to choose between the side in the first-half as CSKA rarely threatened the TNS defence, but there was controversy in the 29th-minute when keeper Paul Harrison parried a long range effort from Alexander Tonev at full stretch with the hosts claiming the ball had crossed the line before he was able to gather it safely.
The Bulgarians' main threat came from Delev, who sent his first effort soaring over the bar and another shot well wide of the far post when well-placed in the box.
It was half an hour before Craig Jones had a chance to take on the home rearguard but, after beating Trifonov to the byline, his cross was easily gathered by keeper Karadzhov.
Delev then had the ball in the net on 37 minutes but was clearly in an offside position.
The Saints resisted increasing pressure in the second-half and were rarely able to escape into their opponents' half.
But they looked capable of pulling-off a shock result until their tired legs conceded the three late goals which probably spell the end of their dreams of reaching the group stages.
