Celtic manager Neil Lennon has accused referee Alberto Undiano Mallenco of being "very pro-Juventus" after his side were beaten 3-0 at Parkhead in the first leg of their Champions League second-round tie.
Despite dominating the match for large periods, Celtic could not convert any of their chances and were punished on the counter as Juve demonstrated a clinical finishing touch in front of goal through strikes from Alessandro Matri, Claudio Marchisio and Mirko Vucinic.
However, Celtic felt aggrieved that the official failed to deal with repeated instances of manhandling during corner kicks. Stephan Lichtsteiner and Simone Padoin were both booked for incidents while the ball was out of play, but Gary Hooper and Scott Brown were cautioned alongside them and Lennon felt his team were not given adequate protection.
"I thought he was poor," Lennon told Sky Sports. "I thought he was very pro-Juventus. I was disappointed with his performance to say the least.
"It's not rugby we're playing, it's soccer. I pointed it out to the referee at half-time in the tunnel area but he just waved me away. I made it clear to the players to flag it up to the referee in the second half, but he ignored our requests. They were being fouled, manhandled. Every time one of my players tried to move he was held. He should have given a penalty on at least two occasions.
"I'd like to know what the interpretation of the rules are in Italy or Spain, because it's blatantly different to what they are in Britain from what I've seen tonight. They were fouling on every opportunity and he was staring right at it. So are the rules different in Spain? Because, on that showing, they must be."
In his ITV interview, Lennon acknowledged that his side's European adventure was all but over for this season.
"We need a miracle,'' he said. "But it's the harsh reality of Champions League football and some of my young players will learn a huge lesson tonight.
"I thought for 70-odd minutes, until the second goal, we were by far the better side - but you can't give away goals like we gave away, sloppy.''
Matri opened the scoring in the third minute after a calamitous error by Efe Ambrose, just back from African Nations Cup duty with winners Nigeria, while Marchisio and Vucinic killed the game off in the final quarter-of-an-hour.
"Efe was poor for the first goal but we had good chances to equalise,'' Lennon said. "Then we switched off defensively for the second goal and the third goal was poor.''
Juve coach Antonio Conte, meanwhile, was delighted that the tactical changes he made to his side for the match worked as desired.
"In the first half I told the lads it was dangerous for us to sit too deep, so Arturo Vidal and Marchisio were crucial to push it up and take the defenders with them. I worked a lot on that aspect," he said.
"We changed something compared to our usual defending, as they had scored 40% of their Champions League goals from corners and set-pieces. We were only surprised once with a header over.
"We did pretty well defensively apart from at times in the first half when we went too deep. It was a good performance. We knew Celtic were a good side and they might not be mentioned among the top teams in Europe for many years, but they beat Barcelona and eliminated Benfica and Spartak Moscow."
Information from the Press Association was used in this report