Thibaut Courtois says Chelsea must maintain their winning sequence to be in a position to pounce if Manchester City slip up. And Courtois reckons the Blues must prove they are the best of the rest if City, who won a 16th successive Premier League game against Tottenham on Saturday, do not relinquish their grip on top spot. "It's important to try to keep on winning and pushing forwards," Courtois told Chelsea TV. "At the moment City is winning. They are far ahead. But you never know in football.