Chelsea midfielder Ramires has insisted that they will not allow complacency to creep into their game despite holding a seven-point lead at the top of the table.
The Blues benefited from numerous defensive errors to beat London rivals Tottenham Hotspur 4-0 on Saturday and take control of the Premier League title race.
Manchester City are said to be their biggest competition and have three games in hand to try to make up a nine-point gap, so Ramires has warned that Chelsea cannot afford any slip-ups.
He told Globo Esporte: "Manchester City have games in hand and a lot can happen.
"We have to keep focusing on a game at a time, we can't fall into the trap of thinking that everything is okay. Any slip-up could be fatal at this point in the league."
Chelsea continue their quest for the championship when they travel to Aston Villa next weekend.