Thomas Tuchel has played down his recent record against Pep Guardiola as Chelsea prepare to take on Manchester City on Saturday.
The Chelsea boss has overseen three wins from three against Guardiola, including last season's Champions League final.
Chelsea go into the game unbeaten so far this season and with the chance to move six points clear of City in the early stages of the Premier League campaign.
Tuchel knows they can take confidence and experience from previous wins, but expects one of the toughest tests at Stamford Bridge.
"We have the positive experiences and we know how much work we put into it," said Tuchel.
"You have to really work hard for it and earn it. Believing you can do it is the most important in sport and on this kind of level we have the belief we can do it.
"We know what it takes to have the possibility to win. It does not take a miracle to win but we need our best performance. This is tough enough and this is maybe the confidence that it gives us.
"But it will be one of the biggest tests in European football."
Guardiola often springs tactical surprises for big games and Tuchel is wary that another may be in store.
"We always try to focus on us but there are a lot of behaviours we need to be aware of," said Tuchel.
"They played a very different line up in a game in Manchester, caused a lot of problems for us. So you never know.
"They have a lot in the pocket, are a top team, have a top manager, have many years of experience."
