Since losing at Everton and their opening Group E game to Basel at Stamford Bridge, Jose Mourinho's team have won against Fulham, Swindon Town and Steaua Bucuresti.
"When you have results like we did against Everton and Basel in the same week, you wait for a reaction and I think the reaction has been perfect," Chelsea's official website quotes him as saying. "Since then we've had some good games and good performances.
"I think you see the real strength of a team when something like that happens, it's been a great reaction from us and hopefully we won't need to react like that again in the future because we will get the right results in the first place.
"It was the most difficult moment of the season so far for us, losing two games in a row was something we didn't want, but we are now back on track and that's very positive."
Chelsea are currently fifth in the Premier League table with 11 points from six matches.