After 11 attempts in the English Premier League, Rafa Benitez's side secured a victory, with Ayoze Perez's thunderous header handing them a 1-0 win over the Hornets over the weekend.
And the Senegal international is upbeat that that moment could be what would turn their fortunes around this season.
"I cannot tell you how important moments like that are.
"You could hear the fans pushing at the end, too. That's the atmosphere we want, and it's up to us to get them pumped up by performing on the pitch and getting results.
"Things went against us at times against Watford. We had three injuries, but we have to congratulate the players who came on because they did very well.
"But finally we can speak after a win, which is a great feeling. We missed this feeling a lot and we are happy now after this result and can enjoy a good, positive week of training.
"It doesn't matter how we get the three points, we just have to, and we were happy with how we won the game against Watford.
"Of course, I've been confident [things would turn around]. Football is about confidence, and when you lose a lot of games like we were then the confidence goes down, so it's not been easy.
"You need character, desire, and people who take responsibility on the pitch. Against
They trade tackles with Bournemouth this weekend, and Diame is confident of their chances against the in-form Cherries.
"Now we can look forward to playing against Bournemouth at St James' Park and we will try to do the same thing," he continued.
"Of course, it was good to grow our confidence higher before another home match against an in-form team in Bournemouth.
"They lost to Man United but we know they are a very good side; they lost to a top team, and they will come to St James' Park with self-belief, thinking they can get the positive result," he continued.
"It will be another tough game but we need to put in another big performance and show the right attitude to make sure we win this game.
"We have picked up some points away, but none at home before Watford - so it was crucial to finally end that run.
"Everyone in the squad knows that it is at St James' Park where we need to pick up the most points, so, of course, it is going to be tough but we need to go for the three points again and make winning at home a habit again."