Brentford were punished for some appalling mistakes in a thrashing at St James’ Park.
Two goals in the space of seven first-half minutes, scored by Bruno Guimaraes and Jacob Murphy, put Newcastle in command.
Ivan Toney’s penalty against his former club pulled one back for the Bees nine minutes into the second half but Guimaraes struck again just two minutes later to crush any real hope of a comeback, and Miguel Almiron added a fourth for the Magpies before Ethan Pinnock’s own goal.
Brentford thought they had taken an early lead when Bryan Mbeumo fired past keeper Nick Pope.
However, the goal was disallowed after VAR showed that Toney was in an offside position when his dummy allowed Shandon Baptiste’s pass to run to Mbeumo.
There was no doubt though about Newcastle’s nicely-worked opening goal – a header by Guimaraes from Kieren Tripper’s cross to the back post.
Worse followed for the visitors when a terrible error by David Raya gifted Newcastle a second goal.
The goalkeeper inexplicably played the ball straight to Callum Wilson, who teed up Murphy for a simple finish.
Dan Burn’s handball in the box gave Brentford hope, with Toney characteristically tucking away the resulting spot-kick, but the hosts’ two-goal advantage was quickly restored when Guimaraes shot past Raya at the near post after Aaron Hickey had lost possession.
Another defensive lapse, this time by the returning Pinnock, gifted Newcastle another goal.
Pinnock, back in action after a knee injury, under-hit a back-pass to Raya, and Almiron nipped in to score.
And a diabolical defensive performance by Brentford was summed up in the final minute by Pinnock diverting Joelinton’s cross into his own net.
Brentford: Raya; Ajer, Mee (Damsgaard 71), Pinnock; Hickey, Dasilva (Janelt 45), Jensen, Baptiste (Onyeka 62), Henry; Mbeumo (Wissa 62), Toney.
Subs not used: Cox, Canos, Zanka, Ghoddos, Roerslev.