The Blues continued their strong form so far this season, keeping out United and managing to score once themselves to record a vital three points and extend their lead at the top of the table to five points, although second-placed Arsenal have a game in hand.
Terry admitted it wasn't a great performance but said his team was happy to work hard in every game to achieve the best possible result.
"Another clean sheet for us today, we talk about the attacking players and midfielders coming back and working hard for the team and that's exactly what we got today," Terry said.
"(The five-point lead) was exactly what we wanted coming into the game, we've been working on it all week. That wasn't the best of games but I think overall we deserved it."
Chelsea have conceded just eight goals in 12 matches in the league this season whilst scoring 29.