Claudio Ranieri said "the Champions League music woke up" Riyad Mahrez, who scored twice as Leicester beat Club Brugge 3-0 on their competition debut.
"It was good because he scored twice, including a fantastic free-kick, and he worked so hard," the Foxes boss said.
"Maybe he is tired of hearing dilly ding dilly dong all the time," the Italian added of Mahrez, who added Leicester's third with a penalty.
"Now we have to stay calm and put our mind to the next match on Saturday."
"Dilly ding dilly dong" is how Ranieri described the imaginary bell he would shake when he thought players were "sleeping" last season - before they stunned the football world by claiming the Premier League title.