The greatest player ever to pull on a Portuguse shirt - he scored 733 goals in 745 matches - lit up world football through along an illustrious career spent mainly with Benfica through the Sixties and early Seventies.
It was the Black Panther's leading role in the 1968 European Cup Final against Manchester United - the year after Billy McNeill had lifted the trophy for Celtic in the city where Eusebio starred for Benfica - that caused the youngster from Lurgan to join his global fan club.
Lennon explained: "When I was about eight or nine, I found an old scrapbook my uncle had.
"He was a huge Man United fan in the Sixties, and the preview to the '68 European Cup final was dominated by Eusebio.
"Then you read about him and you see clips of him playing in the 1966 World Cup.
"That period, from about the mid-Sixties to the early-Seventies, he was probably the best player in the world, certainly up there with Pele."
Lennon has spoken to Lisbon Lion and now Celtic kit manager, John Clark, about Eusebio, who he once played alongside in a charity game as well as playing against him in the 1969-70 European Cup run.
And the current Celtic boss is convinced the positive influence Eusebio brought to the game did not finish when he hung up his boots.
Lennon said: "I think he has been a fantastic icon for the likes of Ronaldo and Luis Figo, and the world-class players that Portugal has produced."
The Celtic manager's sentiments were heartily echoed across the city's Old Firm divide.
Rangers manager Ally McCoist hailed the Portguese superstar as a "proper gentleman".
He added: I have seen footage of him playing for Portugal in the World Cup in 1966 and he was a fantastic talent and a wonderful player."
Ibrox wing legend Willie Henderson became friendly with the former Benfica star during their playing days and called him one of the all-time greats of the game.
The Ibrox hero said: "It is only three or four weeks ago I sent a present out to him to Portugal. It is a big blow to football. He was a wonderful person.
"Most people have heard the name Pele and in many people's minds, he is the greatest player that has ever played.
"But if you are looking at the best players ever, Eusebio has absolutely got to be in the top five. That is how great Eusebio was."