Just four minutes after coming on as a substitute at the weekend against Sheffield United, the 27-year-old found the back of the net.
His arrival into the fray after 56 minutes, along with fellow new signing Karl Hawley, seemed to galvanise the Iron as they looked for their first league points of the season, having struggled for a cutting edge against a nine-man Blades.
Manager Alan Knill has previously made no secret of his desire to add more power to his forward line, and was delighted with the instant impact of his new acquisitions.
“We know what Leon has got, he is a top player and we are lucky to have him here,” he told The Iron Player.
“Both he and Karl, we think, are only going to make us better as a team.
“He actually only came in this morning, we did the deal on Friday and he travelled up on Saturday.
“When you are not performing as a team and everyone is a little bit down, you need something to give everyone a lift, and players of the quality these two are definitely helps everybody.
“What Leon brings you is a presence in and around the box, and he scores goals.”
Despite scoring just four minutes into his debut, the Iron boss still feels that it may take a week for Clarke to fully integrate into the squad.
“The good thing is that for the first time since the start (of the season) we don’t have a midweek game,” he continued.
“That will give him some time to learn the style of play but I have to say from what I have seen already he looks like he is okay in terms of fitness.
“Leon has obviously been at Charlton while Karl has been with various clubs, so you would have to hope they are both up to match fitness.
“But even if they are not quite, the impact they had for us out there was plain for all to see.
“I won’t lie, it has been difficult finding the type of striker we were looking for, especially at a price we could afford.
“But once Chris Powell (Clarke’s boss at Charlton) had said yes we knew we might have a chance with him, because last year he went on loan to Chesterfield and they were in a similar position to the one we are in now.
“That was how we sold it to him, come here and score lots of goals, just like he did there.
“Luckily for us he jumped at the chance, there is no substitute for playing league football and thankfully that is his main priority.”
After making no secret of his desire to add a player with the power of Clarke to his squad, the Iron boss explained that the circumstances under which Hawley made his way to Glanford Park were somewhat different.
“I was only talking to (Notts County boss) Keith Curle about him on Tuesday,” he added.
“Obviously they had him at Notts County last year and Keith said he was sharp and scores goals.
“Then on Thursday, out of the blue, we had a phone call asking us to have him in for training, which we did.
“We had some others in as well, so there was a real buzz about things.
“What attracted us to Karl is that he is different from what we already have here.
“He likes to get in behind defenders, which is something we didn’t really have.
“He is nippy and bright, and has a real eye for goal.”
See much more from Alan Knill, Leon Clarke and Karl Hawley on The Iron Player.