Lescott's side are currently five points ahead of Spurs at the top of the Premier League but the England international claims that City should be concentrating on second-placed Manchester United.
The 29-year-old said: "We know if we win on Sunday it would open up a gap between us and them. But no disrespect to Spurs, our main rivals are Manchester United. They are second in the league and our focus should always be on the team immediately behind us.
"As much as the points on Sunday are vital because of the gap to Spurs, they will be more important to pull away from Manchester United."
Manchester City beat Spurs 5-1 in their last match in August.