The loss equalled the worst ever suffered at home by Celtic in Europe, 3-0 against Paris Saint-Germain in 1995, as goals from Alessandro Matri, Claudio Marchisio and Mirko Vucinic extinguished Celtic's hopes even before the second leg in Turin on March 6. Although Celtic competed well for a large section of the game they had neither the attacking threat to break through the Serie A leaders nor the defensive ability to keep them out, with Efe Ambrose culpable for the first goal before the Nigerian squandered a chance to equalise with a header.
But the manhandling of Celtic players by Juventus defenders during set-pieces infuriated the Parkhead crowd and Lennon, who was unsparing towards Mallenco. "The ref was warned by our players to keep an eye on what was happening because they were being fouled at every set-piece. But even though he was looking straight at it, he did nothing," said the Celtic manager.
"I pointed it out to him in the tunnel at half-time, but he waved me away. I told the players to keep flagging it up, but he kept on waving them away. This was meant to be football, not rugby. Are the rules different in Spain and Italy from Britain? On this evidence they must be."
One of those to cry foul over the repeated actions of the Juventus defenders was Emilio Izaguirre, the Celtic full-back insistent that his side should have been awarded penalties at a series of corner kicks. "There was so much pushing and shoving in the box. The referee did not seem to see too much," said the Honduran. "I spoke to him in Spanish. Every time there was a corner or a free-kick, I was saying to him about the fouls, but he wasn't listening to me."
Celtic had also gone to considerable effort to ensure Ambrose was back in time to play after appearing in the Africa Cup of Nations final for Nigeria in South Africa on Sunday, but he had his worst night for the club. "Maybe it was a gamble playing him, you always question decisions after the event," said Lennon. "But the mistake at the start wasn't down to tiredness and the miss was just that, a miss."
Juventus remain unbeaten in all Champions League games this season have conceded only 20 goals in 32 Serie A and European games. Uefa's statistics brought Celtic the meaningless consolation of showing they had 17 attempts on goal to Juventus's nine, with 10 on target to the Italians' seven. But while Celtic sent a series of chances straight at goalkeeper Gigi Buffon, Juventus were deadly.
"Celtic are a very good team, we knew this," said coach Antonio Conte. "They showed it in the group games and they showed it again tonight. It is a fantastic crowd, never mind an extra man it was like two extra men for them."
But Conte refused to be drawn on referee Mallenco or Lennon's anger about how his defenders escaped punishment. "Quite often in Italy we have the bad habit of over-criticising so we will leave to the Celtic manager to criticise this evening."