Although the Paisley men have now drawn level with third-bottom Ross County, and put six points between themselves and rock bottom Dundee, Lennon is still a frustrated man at the lack of firepower coming from his men.
The Buddies were held to a 1-1 draw by nine-man St Johnstone after drawing a blank in a 0-0 stalemate at Ross County in their previous SPL outing.
Now ahead of Saturday's trip to SPL champions Celtic, Lennon has demanded his men find a cutting edge.
He said: "That is two weeks now and I have been hammering on about the same thing and that is that we are just not ruthless enough. Right now we are not producing enough of an end product and that is both very frustrating and also costly.
"Although we drew with St Johnstone it felt more like a loss given that they were down to nine men at the end and we did not get the winner. Yet all that was missing was that final ingredient.
"I couldn't fault the boys in terms of their effort and commitment and for the level of opportunity they are creating.
"But we have got to put more of them to bed. Obviously we are not going to create the same number of chances at Parkhead this weekend but that only means that being absolutely ruthless when we do get an opportunity is going to be even more important.
"But end product is the difference between success and frustration in the SPL and if we want to push on up the table we must supply more of it."
But the Buddies boss had warm words of praise for teenage midfielder John McGinn who started his fourth game on the bounce for the Paisley men.
Lennon said: "John McGinn is a special talent and one who is now in our midfield entirely on merit. I was a wee bit disappointed that he lost Murray Davidson for the St Johnstone goal but the great thing was that when he came in at half-time John held his hands up immediately and owned up to his error and that honesty was refreshing and highly laudable.
"But the great thing for John, and I have stressed this to him, is that these type of experiences will provide him the ideal learning curve from which he will, I believe, develop into a top-class midfielder."
Lennon added: "The priority for us was to put an end to our poor run and we have done that and now consolidated ourselves alongside Ross County. Going to Celtic Park is going to be a huge challenge but one we are looking forward to."