Celtic striker Leigh Griffiths says Ukrainian referee Serhiy Boiko laughed at him after disallowing his goal in the 1-1 Europa League draw against Astra Giurgiu in Romania on Thursday.
Substitute Griffiths, on for Stefan Scepovic in the second half, had a winner in the net with minutes remaining, only to see it ruled off for an infringement.
Afterwards, a rather irate and bemused Griffiths said: "I've watched it back and everybody in the changing room has watched it back and they said it's not a foul.
"I knew it wasn't a foul, I just stood my ground and the boy jumped into me. I read where the ball was going to go and I knew that he'd jumped awkwardly and was going to fall backwards and the ball fell to my feet and I've put it away.
"The ref didn't even blow straight away, he let me go away and celebrate and then brought it back and started laughing about it. It seemed like every foul he gave against us he started laughing.
"It was a poor result in the end for us, we dominated large spells of the game and with the chances we created we should have walked away with the three points. It's just one of those things and in our next game we've got to take three points to get through the group stages."
Celtic manager Ronny Deila concurred with Griffiths, saying: "Everybody who has seen it again says it should be a goal. Leigh also thinks it was a goal. He said he didn't do anything, so we should have won 2-1.
"Sometimes that happens and we have been lucky some other times. This time it has gone against us."
Celtic, with eight points from four games, will go through if they beat section leaders Salzburg at Celtic Park later in the month.
Salzburg beat Dinamo Zagreb 5-1 to move on to 10 points and the Scottish champions take on the Croatian side away in their final section game in December.
Deila, however, believes qualification should have been confirmed against Astra.
He said: "I think we deserved to win. It was two points lost. We were the best team tonight, in the first half we were excellent and scored a nice goal.
"In the second half we controlled it quite well but they scored a fantastic goal. There was nothing we could do about it -- it was a fantastic shot.
"We had enough chances to kill the game and to win it -- but in the end we have one point and while I am not happy with that, it is better than nothing. Maybe we could have played more forward and attacked more, but we seemed quite confident and had control. I am frustrated by that and we have something to work on when we go 1-0 ahead. We have to keep on playing offensively instead of trying to win the game 1-0.
"The performance was OK, the results should be better."