Ben Dawson says his players learned a "harsh lesson" at St James' Park after being hammered by Manchester United.
In a one-sided game, Newcastle blew their chance of winning the title in spectacular style as the Red Devils ran out 5-0 winners.
It means United's best chance of promotion will now be the play-offs in Premier League 2.
Looking back on the game, Dawson said: "We created a great opportunity in the first minute when Rosaire Longelo went clean through but Paul Woolston came racing off the line and made a good save.
"After that it was one way traffic and the harshest of lessons against the best team we've played this season.
Newcastle United U23s 0-5 Manchester United U23s match report: Magpies handed harsh lesson
"I think gave the lads an insight into what it's all about in terms of quality and pace all over the pitch.
"I didn't think we worked well as a team to solve those problems.
"As a consequence we got there a second too late or a yard too short and it made it a difficult night for us.
"We only had one chance in the full 90 minutes.
"I'd like to think they will use this experience to try to improve themselves."
United do still have a chance of winning silverware in the Premier League Cup and have a semi-final away to Leeds coming up in due course.
Dawson said: "If you wanted it to happen any time it's now (ahead of a cup semi-final vs Leeds).
"We are hoping it is just a blip in the system.
"The lads have a couple of days to get their heads right and recover.
"Then we will be back in on Thursday to put some of those things right."
United could also do with a win in their final Premier League 2 game against Middlesbrough on April 28 to secure a home draw in the play-offs.
Dawson said: "You are going out to win every game
"A home draw in the play-offs would be nice but we have to forget about the play-offs and concentrate on performances.
"It's the only thing you can control.
"We didn't do that and paid the harshest price."
