Mourinho's Lilywhites came from behind to seal three points against their local rivals in the North London derby.
Belgium defender Toby Alderweireld said Tottenham's 2-1 victory against Arsenal on Sunday was 'massive'.
The Spurs centre-back also admitted playing behind closed doors is 'difficult' as it would have been a 'totally different atmosphere' if the fans where present.
Jose Mourinho's Lilywhites came from behind to seal three points against their local rivals in the north London derby as Heung-min Son capitalised on Sead Kolasinac's mistake to cancel out Alexandre Lacazette's beautiful opener before Alderweireld wrapped up the win with a late header.
Speaking to Sky Sports after the win, the 31-year-old said: "I think it's massive for us. I think we really wanted to win this game, you know it's difficult without the fans, it will be a totally different atmosphere but I think we did everything that we could. We fought.
"I think we did have a little bit of luck to get three points today.
"I think with the goal, because against Bournemouth, you missed a little bit of luck to get the last pass, so I think today we had the little bit of luck to get the 2-1."
And, while speaking to BBC Radio 5 Live, the match-winner said: "It was a good cross, I thought it was a little bit too high and I got my head underneath it. It was a nice goal."
On hurting after recent defeats, he said: "It always does, people don't see how hard we work. We tried to do better today and showed there is a character in the team, like fighting spirit.
"Defensively we are getting much better in the last couple of games and you have seen we have quality upfront because we could have scored more than two goals.
"Sometimes you need some confidence, like a good win and get the momentum a little bit. The only thing we can do is work hard. What people don't see is that everyone is putting everything into it and I believe that things will change. Today is a very important win for us and the fans."