Chelsea recorded a stunning 2-1 victory over Manchester City at the Etihad Stadium on Saturday evening to delay the hosts title party.
Raheem Sterling opened the scoring just before halftime. Aguero missed from the spot few minutes later.
Hakim Ziyech restored parity for Chelsea just after the hour-mark.
Marcos Alonso scored a late winner to give Chelsea the maximum points.
Tuchel believes the win will give his team the confidence to go all out for a win in the Uefa Champions League Final between both teams later this month.
“It increases our self-confidence in a natural and healthy way because everybody knows we have to restart on Wednesday (against Arsenal in the league).”
Chelsea have leapfrogged Leicester City in the third position a point above the Foxes with three games to go.