The midfielder netted his third goal in as many games in Tuesday's 2-0 Champions League play-off round, first leg win against Helsingborgs in Sweden, to follow up his recent strikes against Aberdeen and Ross County.
It is a huge turnaround in fortune for Commons after finding the back of the net just once last season after being plagued by injuries and a crisis in confidence.
However, the former Derby player has started the season in great form and as his side prepare to take on Inverness Caledonian Thistle the Hoops boss hailed his contribution to their fine start to the season.
"This time last year, he probably couldn't have scored the goal he got for us in Helsingborg," Lennon said.
"The level he is playing at is great and his fitness is far, far better. That makes him a lot brighter on the ball in his thinking. He's always been a good quality player and goalscorer. I thought he was class on Tuesday and had a big hand in both goals.
"His play in general was very good. There was a wee bit of confidence lacking in him at times last season. Sometimes he is his own worst critic.
"He worked really hard during the close season and he's a bit more relaxed in his role now. He knows what we think of him, which helps as well. He's pretty low maintenance and he's experienced enough now.
"Sometimes he just beats himself up a little bit but I think he's gone past that stage. If you go through a period like that, you come out of it all the better for it and Kris is doing that."
Celtic face a huge injury list going into the game with five players struggling with knocks and Lennon admits he may have to rest some with the return leg against Helsingborgs in mind.
"Joe Ledley rapped his groin, Thomas Rogne is struggling with his ankle, Beram Kayal is feeling his ankle and Scott Brown had a touch of cramp towards the end," the Celtic manager said.
"Kelvin Wilson has a touch of shin splints but he should be okay for the weekend. We will have Victor Wanyama back and Paddy McCourt will be fit.
"So we will have to see how Joe, Beram and Thomas are and also Kris Commons, who, ever since the Inter Milan game, has had a problem with his ankle and we will see how he is. These guys might have to shut down for a few days."
Terry Butcher's Inverness Caledonian Thistle are also unbeaten this season and defender Simon King has warned Celtic his side will provide the Hoops with another torrid test in the Highlands.
"It's going to be interesting against Celtic on our own patch," King said.
"We're not going to be turned over easily. We'll show the same battling qualities we did at Hearts. We were two goals and a man down and we still came back.
"The spirit and togetherness among the players is already terrific and belief is growing with every game.
"With a good week's training behind us, we'll go out and look to get three points. We're confident we can give Celtic a really good game. We have shown great character to keep our unbeaten start going and we're not going to give that up easily."
Saturday
Inverness CT v Celtic, Dundee v Ross County, Hibernian v St Johnstone, Kilmarnock v Dundee United
Sunday
Aberdeen v Hearts, Motherwell v St Mirren
Source: AFP
Source: AFP