The 27-year-old centre-back earned a valuable point with a 94th-minute header to earn a 1-1 draw with Aston Villa at St James’ Park on Friday night.
Steve Bruce’s side have now earned three straight draws to slowly move towards safety, with a two-point cushion with 10 games remaining, including the next match against rivals to beat relegation Brighton.
Lascelles told NUFC TV: “We’re confident. As players, we know we’ve got enough quality. You can see that it’s there, it’s just the final pass or the final decision or the final run.
“If we can get that right, the amount of chances we create, we can convert them into goals. We’ve just got to stick with it – we’ve still got a fair few games to go – stick with it and just keep battling on.
“It’s huge for us. Every game is massive now, it’s like a cup final and that’s the attitude we need to have going into every game.
“We’ll go down to Brighton, try to get a win and after the international break, reset and go again.”
Lascelles’ bullet header from substitute Jacob Murphy’s cross came in the nick of time, with Villa having taken an 86th-minute lead when Ollie Watkins’ header hit defender Ciaran Clark and looped into the net.
Defeat would have piled the pressure on under-fire head coach Steve Bruce and his players and while a draw was not the result the Magpies needed, the manner in which it arrived and the fact it was achieved without injured trio Callum Wilson, Allan Saint-Maximin and Miguel Almiron provided cause for optimism.
Lascelles said: “Considering we were down, losing 1-0, to come back from that with a few minutes to go, obviously it’s nice feeling.
“However as players, we need to look at ourselves. We shouldn’t really have been a goal down, we should have been a goal or two up and that’s the mentality we need to have.
“We need to convert these points into wins now. The performances have gradually been getting better and games like this where we’re on the front foot and creating chances, we need to win them.”
For Villa boss Dean Smith, who was himself without playmaker Jack Grealish through illness, there was frustration at a failure to replicate the club’s early-season form.
He said: “That’s happening across the league at the moment, I don’t think it’s just Aston Villa. We’re certainly trying to create more opportunities – that’s probably been my biggest bugbear.
“Since our break for Covid, I don’t think we’ve created as much as we should do and it’s something that we’re trying to get back.
“I certainly can’t fault the will to win and the being hard to beat mentality, but I think in general, there’s just been a sloppiness around the league.”