Howe has endured a difficult period since the end of last season, with Newcastle unable to make significant signings and forced to sell players to comply with the Premier League's spending restrictions
Just days after Howe said Newcastle's transfer policy would make sustained take a "lot longer", the club's chairman Yasir Al-Rumayyan was at St James' Park to see the hard-fought success against Tottenham.
Newcastle are unbeaten in their first four games, while Tottenham, who dominated for long periods, were beaten for the first time this term.
"It's massive, isn't it?" Howe said. "You need to win at any stage but I think when there's difficult moments -- and this transfer window has been tough for us -- then it's even more important.
"It just enables you to see things clearly and to move forward with positive momentum.
"Hopefully we can do that. Today was a tough game, but, as I said, we found a way to grind out a win and hopefully those are good signs for the rest of the season."
Harvey Barnes' superb finish gave Newcastle the lead in the 38th minute, before Tottenham equalised 11 minutes after the interval when Dan Burn turned Brennan Johnson's cross-shot into his own net.
Tottenham paid for wasting a series of chances to go ahead as Jacob Murphy's pass teed up Isak in the 78th minute.
"I don't think we're playing as we would like, I think that's obvious. I don't think we're playing with enough control and composure. But what we are showing is the defensive and aggressive qualities that you need," Howe said.
"I have to say we're defending very well but on the ball, I think we've got a lot of work to do. Our attacking play has not kicked into rhythm yet."
Tottenham boss Ange Postecoglou admitted his team had been punished for not killing the game off.
"We controlled it for the most part, nullified most of the threats that Newcastle have," he said.
"I thought for the most part, we handled that really well and then gained the ascendancy in the game.
"We just needed to kill it off and it was a disappointing second half, where we switched off a little bit.
"But the game should have been all over by then so it's another sore one, unfortunately."
