The Lions looked much livelier in the second half with McLeod working well with new striker partner Neil Harris and it was neat combination of passing between these two that lead to the goal and secured the win for Jackett's men.
"It looked like a draw today," said the Millwall boss after the game. "But we won it with a very well-taken goal.
"It was a good move and a superb cross form Dave Martin which was finished off with an excellent header by Marc Laird. He's hard to pick up when he come in from deep like that and it was good technique by him to head it down like that.
"He gave the keeper no chance."
And Jackett was quick to single out McLeod as the reason for the change in fortunes.
"Izale McLeod played well on his debut - we've got a full week with him now so hopefully he'll be even better next week.
"He's a different kind of player to our other strikers because he wants to get in behind defenders - I think he'll complement the players we already have. He wants to play but he didn't have the opportunity at Charlton but hopefully he can do here."