Spurs got the better of City 4-1 at White Hart Lane in the Premier League on September 26.
It was one of the best performances from Tottenham, and left-back Davies has explained the effect the win in North London had on the players.
“It was a big performance and a big confidence boost,” the 22-year-old Wales international told The London Evening Standard. “We started the season putting in good performances but we weren’t quite getting the results and that result set us on our way.
“We realised how good a team we have here and we’ve worked on things since then and got better. Maybe it’s not so noticeable but in games where we’re cruising, where you think we might get a bit sloppy, we’re killing teams off.
“We don’t give away goals through sloppy mistakes and it’s about setting the bar high for everyone out there.”
Tottenham have gone from strength to strength since that win, and will be backed by many Premier League observers to pick up all three points against City away from home at the Etihad Stadium on Sunday evening.
Spurs are second in the league table at the moment with 48 points from 25 matches, five points behind leaders Leicester City.
The North London outfit are one of the top contenders to win the Premier League title this season. Mauricio Pochettino’s side, though, will face stiff competition from Leicester, Arsenal and City.