Manager Chris Hughton insists Newcastle have plenty more to do before being sure of promotion from the Championship.
The Magpies moved a step closer to making an immediate return to the Premier League after a 5-1 win over fourth-placed Cardiff at St James' Park.
That sent Newcastle six points clear of West Brom at the top of the Championship table, with Nottingham Forest a point further back and Cardiff 14 points adrift.
But Hughton has urged his players not to get ahead of themselves after extending their unbeaten league run to 15 games.
"We had a good day today against a very good side that hadn't lost for a while," he told Sky Sports News.
"We know it'll go right to the end because everybody has their own agendas and they'll be pushing.
Look after business
"We very much expect West Brom and Forest not to lose too many games so we've got to look after our own business."
Newcastle charged into a 3-0 lead inside 15 minutes, with Andy Carroll scoring twice - either side of a Gabor Gyepes own goal.
Second-half substitute Peter Lovenkrands then bagged a well-taken brace before Cardiff sub Aaron Wildig claimed a late consolation with his first senior goal.
The Bluebirds have been unable to bring in new recruits as £3million raised from advance season ticket sales had to be used towards paying off a £2.7m tax bill, which must be settled by 10th February.
Financial problems
They still have a five-point advantage over seventh-placed Blackpool and manager Dave Jones has warned the Bluebirds faithful to expect a rollercoaster finish as they aim to hang onto a play-off berth.
"We probably just got overrun by one of the best teams in this division, with the biggest squad," Jones said.
"We couldn't compete and when we need to change things, we can't.
"We've just got to get on with it and the fans have got to accept that because it's going to be up and down from now unless we change things, and at the moment I can't see any light at the end of the tunnel for that."
Very true Chris, it is going to get tougher in the coming weeks, so the Magpies have to realise this, every single game a 'Cup final' game to our opponents and we need to keep aware of this. To beat the Magpies is something they all want to do and do it badly!
