City responded to being knocked out of the Champions League by moving to within three points of top-flight glory, courtesy of goals from Gabriel Jesus, Ilkay Gundogan and Raheem Sterling in an emphatic victory for Pep Guardiola's men.
"Today we scored the goals and defended better and we deserved to win it," De Bruyne told Sky Sports News.
"It's been a tough two weeks for us with five games. [Tottenham] didn't have a game for a week and that's the advantage they had. The mental toughness of this team is unbelievable.
"We're almost there, we knew we had to win two of six games. That's not bad odds for us. We need to do our thing and hopefully we can finish it off next week."
City will claim the title if they beat Swansea City at home next Sunday, or if Manchester United lose to West Bromwich Albion at Old Trafford this weekend.