Celtic moved through to the semi-finals with the only question mark over his team in a one-sided victory being whether Kris Commons had scored a hat trick or whether the first goal should be credited to Liam Craig after a substantial deflection but Lennon received an unequivocal answer from his team in the wake of the 2-0 defeat by Kilmarnock on Saturday.
"I told them: 'This time last week you were well motivated, you were in a nice climate, going out into the Nou Camp, Tonight it is different with maybe 15,000 people there but the attitude has to be the same'. "I got that. I enjoyed watching the team play tonight. That is a marker, I hope, for a concerted period of good performances," said the Celtic manager.
"That is what I am demanding from the team. We have moved on from the weekend but I cannot forget it. I want the players to forget it but I will be demanding more for them as the season goes on."
Lennon admitted the performance against Kilmarnock had bemused him, admitting he had been "scratching my head". He added: "We fell below our standards but that was a fantastic response."
He said his team had "been aggressive in our pressing, aggressive in our tackling". The "dominant performance" included goals from Charlie Mulgrew and Gary Hooper, who was taken off at half-time as a precaution over a slight hamstring strain. Scott Brown, the captain, was also removed, but both players are expected to be fit for Saturday's trip to Tannadice to play Dundee United.
Lennon, who said he will not be discussing next week's match against Barcelona until the trip to Dundee has been negotiated, praised the "bright and alert" Commons and said he was right to claim his hat trick.
A sheepish Commons seemed less sure, inquiring of the press: "Have they given it to me?" He admitted, too, that his effort "was not going in and it was was more a cross than a shot". He was awarded the goal by some agencies but the stadium announcer gave the goal to Craig, the St Johnstone midfielder.
He was more convincing about the reasons for Celtic's facile victory."We worked hard, we played at a good tempo and got the rewards for our hard work," said the Scottish internationalist.
Steve Lomas, the St Johnstone manager, admitted Celtic were "a class apart" in front of 14,399 fans.
"Sometimes you have to pay credit to the team you play against and Celtic were a class apart and showed why they are champions of Scotland and able to go to Barcelona a give them a game," he said.