Real Madrid defender Sergio Ramos has warned against getting too carried away with his side's fine start to life under Jose Mourinho.
Ramos also believes his side need to try and start killing matches off sooner to avoid suffering any nervy moments later on.
The Spain international was speaking after his side's 2-0 home win over local rivals Atletico - a victory that kept intact an unbeaten record against their neighbours that stretches back to 1999.
The win also kept Real a point clear of Barcelona at the top of the Primera Division standings, while it improved their impressive record under Mourinho to 11 wins and four draws from 15 competitive matches.
Real, who have already booked their spot in the last 16 of the Champions League as well, could hardly have asked for a better start to the campaign, but Ramos preferred to keep things in perspective.
"Whenever you win there's euphoria because it's important to win the derby and continue in first place. (But) at the moment we can't go around with our chests stuck out because there's a long way to go," he said.
"We are happy and pleased, but are staying calm."
Ramos also believes there are areas of Real's game that need improving.
Mourinho's men stormed into an early 2-0 against Atletico thanks to goals in the opening 20 minutes from Ricardo Carvalho and Mesut Ozil, but the home side could not add a third goal and they survived a few scares as Atletico threatened a comeback.
Real ended up winning relatively comfortably but, as in their victories over AC Milan, Espanyol and Osasuna, Ramos would like to have seen the contest settled earlier.
"We went out from the start looking to win the game, but we need to learn how to finish matches off," he said.
"Nobody doubts the quality of Atletico Madrid and you noticed that because we relaxed a little and they took advantage.
"We need to continue improving throughout the season. Hopefully the good run will continue."
