The only loss and two draws the spurs had this season in the premier league were both away games, and palace is known to be a hard nut to crack at home so it's very possible the spurs may draw or have a very hard time winning and if they succeed in snatching three points from palace tonight, I don't expect more than two goal because palace is really going to be tough and wouldn't allow themselves concede so much at home.
I think you mistook Spurs' loss to Fulham in the Carabao Cup second round for the Premier League. The team lost through a penalty after a 1-1 draw and Tottenham conceived through an own goal scored by M. van de Ven in the 19th minute and Richardson equalised in the 56th minute. But they were unlucky to lose the game on penalties by 5-3. Spurs have not lost any game in the premiership this season.
Yes, this is the right time for Chelsea to take the opportunity when the situation of big clubs is having a very busy schedule to appear in the Champions League, and from the last few appearances Chelsea has shown quite good performance after being able to keep up with big clubs like Arsenal, they are more confident to continue to get additional points to secure their position and the next match Chelsea will play against Brentford and from this match I predict it will likely end in a draw because even though Brentford is not very strong, I am quite sure Brentford knows Chelsea's weaknesses so it will be a little easier for Brentford to score while Chelsea also doesn't want to lose this match.
Liverpool coach Jürgen Klopp once said that Chelsea has more advantage over many of the top clubs in the EPL because they have quality players and fewer engagements. But the Blues are yet to start maximizing this privilege since they still not winning games. Their performance in the match with Arsenal was commendable but let's see what they will get from the match against Brentford tomorrow.