The Hibs manager achieved the 12,500-to-one shot at Kilspindie Golf Club in Aberlady, East Lothian.
His agent and close friend Martin Reilly revealed: “I heard about it around 10 minutes after it happened - he made a point of phoning me!
“He’s a bit of a dark horse as a golfer. He has come close to it a few times so I wasn’t surprised.
“He doesn’t golf there normally. A friend invited him up and he certainly gave them something to remember. He’d played well and got the hole-in-one, so he was delighted.”
Lennon’s golden shot came at the 167-yard par-three eighth.
After finishing his round, he headed for the club shop so Kilspindie’s resident professional Graham Sked could sign the ball for him.
“He was in good form,” said Mr Sked. “It’s tradition to sign the ball after getting a hole-in-one. I’ve been the club pro here for 25 years and it’s really rare.”
Lennon’s Hibs team have been knocked off the top of the Scottish Championship by Queen of the South but, off the park, his luck seems to be in.
It can be costly for players in the UK and US, though, where it is customary for a golfer to buy a drink for his playing partners and everyone in the clubhouse when they return from their round.
It hits pockets even harder in Japan, where it is tradition to buy your playing partners expensive gifts.
Mr Reilly added: “I don’t know much about the custom myself because I’ve never had one. I’ve never even come close - I’m lucky if I hit the green.
“He’s a good golfer so I’ve had to stop playing rounds with him - he’s taken too much money off me!”
Kilspindie, formed in 1867, is the 35th oldest golf course in the world and is a popular spot with former footballers.