Jan Kozak bemoaned a missed early chance by Marek Hamsik and insisted Wales had more luck as they beat his Slovakia team in their Euro 2016 opener 2-1.
Ondrej Duda got Slovakia back on level terms after Gareth Bale's early free-kick, but Hal Robson-Kanu squeezed in a late winner to snatch the points.
Hamsik had been denied by a sliding Ben Davies block after just two minutes in Bordeaux and Kozak felt it was a decisive moment in the game.
"We had a clear-cut chance but Hamsik didn't score and we conceded from a free-kick," the Slovakia coach said.
"It affected the way the game developed, we weren't very sure on the ball, we lost possession quite easily.
"I think after half-time we did our best to succeed, we equalised and towards the end both Wales and us tried to get the win in an open game.
"I don't think they were better, they had more luck, a draw would have been fairer."
Kozak added that he was unsure whether goalkeeper Matus Kozacik should have done better for Bale's free-kick after the goalkeeper took a step the wrong way as the Real Madrid star struck the set-piece.
"It's difficult to see from the bench whether the keeper could have saved Bale's goal," Kozak said.
"It was a typical Bale shot from a free-kick. He's a top player and we have to respect it.
"Of course any defeat is unpleasant, especially at a European Championship.
"I knew that whoever scored the first goal would have a great advantage because Wales have a well-organised defence and up front they have a very dangerous man who can make a difference.
"When I brought on Duda and [Adam] Nemec it was a bit of a risk, but you have to deal with these scenarios. We could have prevented the second goal, but that's football."
Slovakia's next Euro 2016 match sees Kozak's team take on Russia in Lille on Wednesday.