The Reds fell behind Manchester City into second on Sunday after being held to a 0-0 draw by Everton in the Merseyside derby.
Jurgen Klopp’s side had been perched on top of the table since December but are now one point off the pace with nine rounds remaining.
However, Mourinho believes that Liverpool’s 1-1 draw with the Foxes at Anfield on 30 January was a key moment, as they failed to take advantage of City’s surprise defeat to Newcastle United.
“I had that little feeling when City lost a match and Liverpool drew at home,” the Portuguese told beIN Sports.
“These are the matches where you have to do it and get that opportunity. When they lose one, you must win the next one. Liverpool lost a few opportunities.
“City lost and the next day they got the positive energy back because Liverpool drew.”
Mourinho, who lost his job at Old Trafford in December, believes the league title is now City’s to lose.
“Liverpool lost the lead, City is now top of the table,” he said.
“They have the destiny in their hands and Liverpool lost the control. Two points lost here and there, they have lost a few important points to leave them in the hands of others.
“I think the psychological factor is very important. Now they have to think about others and not just themselves.
“They are thinking about two matches every weekend – their match and City’s match.”