The Foxes secured a 1-0 win in the first leg of their semi-final clash with the Hornets on Thursday.
A solitary effort from David Nugent was enough to earn them a narrow advantage, but Pearson knows there is still all to play for.
Taking that into account, he claims that he will send his side out looking to build on their lead at the weekend, rather than defend it.
Pearson told Sky Sports: "It's half-time - a tight game, two good sides. We were able to take a chance towards the end when it looked as though it was probably going to end up 0-0. It's all to play for, for both sides still.
"(We'll have the) Same mind set as it would be with any other result. We have got to be positive and we will try and win the next game as well. I said it before the game, we will try and win both games. I think both sides will take that approach.
"The play-offs are always a bit difficult to negotiate, in terms of anything can happen. There is a lot to play for and both sides will feel they have got a good chance."
On Nugent, who had gone 16 games without a goal heading into a meeting with Watford at the King Power Stadium, Pearson added: "For any striker to go any length of time without scoring effects them to a certain extent, but with David Nugent in particular - when you look at what he gives the team in terms of his work rate and his enthusiasm - he's always going to be giving something positive to the team.
"It was only a matter of time before he scored again and it was an important goal for us."