The Blues ended up on the wrong end of the scoreline for the first time in 22 games in all competitions at Newcastle on Saturday as substitute Papiss Cisse's second-half double secured a 2-1 victory for the Magpies.
However, keeper Courtois insists they must forget the disappointment of defeat at St James' Park as they prepare for Wednesday night's Champions League clash with Sporting Lisbon before turning their attention to Hull's visit to Stamford Bridge and the business of winning the title.
The 22-year-old told Chelsea TV: "That's the most important, that we are still leaders and from the next game on, we will fight to keep that bonus up and make the gap bigger.
"There are only difficult games in the Premier League and we know that
The next game is in the Champions League at home and then against Hull, we have to win in front of our fans."
Chelsea, who have now lost on their last three league visits to St James' Park, left the north east for the second time in a week wondering how they were doing so without three points after dominating for long periods just as they had done at Sunderland seven days earlier, when they emerged with a 0-0 draw.
On this occasion, however, their inability to turn pressure into tangible reward was punished by their hosts, who defended manfully before striking decisively on the counter.
The deadlock was broken with 57 minutes gone when Cisse, who had only been on the pitch for four minutes, slid home Sammy Ameobi's cross after Gary Cahill could only help the ball into his path.
Chelsea immediately launched a fightback and came desperately close to an equaliser with 12 minutes remaining when Eden Hazard's shot came back off the post with Newcastle's third-choice keeper Jak Alnwick, who had replaced the injured Rob Elliot at the break, beaten for the first time.
But worse was to follow as the Magpies turned defence into attack for Moussa Sissoko to play in Cisse for his second.
Substitute Didier Drogba gave the visitors hope when, after defender Steven Taylor had been dismissed for a second bookable offence, he glanced home an 83rd-minute Cesc Fabregas free-kick, but despite having 13 minutes, including six of stoppage time, in which to find an equaliser, they could not manage to beat debutant Alnwick again.
Courtois said: "Obviously we are disappointed with the result
We tried our best to win this game, and it was a hard game
We were a little bit unlucky.
"At 2-0, it's harder
We tried to fight back, we scored to make it 2-1, but then the ball wouldn't fall right for us and we couldn't draw this game and maybe then win it, so obviously we are disappointed.
"But we will work hard again tomorrow in training to win the following games
Everybody worked hard and gave it all on the pitch to win this game, but we know here it is difficult and we went down against them.
"It was a hard game, but we have to stay positive
We are still leaders, but we know these games to be champions you have to win, so from the next game on, we will try our best to win all the games if possible."
Source : PA
Source: PA