Newcastle have not turned the corner yet despite their 2-1 victory at Tottenham on Sunday, according to manager Steve McClaren.
Ayoze Perez scored three minutes into stoppage time to give McClaren's side a second successive win, following last weekend's home victory over Liverpool.
They are now out of the relegation zone but only two points above 18th place.
"We need more performances like that," McClaren said. "We have been inconsistent."
The 54-year-old former England and Derby manager added: "It's answered the critics we have had over last four weeks and it was a great performance in the second half and a great result.
"That is what we are, a bedrock of discipline and hard work. We have talented players and they know how to win. We just have to do it consistently.
"But we haven't turned the corner yet."
Tottenham came into the game on a superb run of form, having not lost in the league since the opening day of the season.
The home side got off to the best possible start as Eric Dier headed home shortly before the break.
However, McClaren paid tribute to the positive attitude of his players despite the setback.
"There have been so many times when I have gone in at half-time and the dressing room has been silent," he said.
"I was angry at the goal but the players were fabulous at half-time.
"It was so vocal, such a determination in the players not to go down the same path as they usually do.
"They took it on board," he added. "We haven't had back-to-back wins for over a year and to do it was immense.
"You can talk and talk but to see them do it on the pitch is great."
Newcastle levelled when substitute Aleksandar Mitrovic tapped home after a scramble inside the six-yard box before Perez struck deep into stoppage time to give United their third win in five games.