Alejandro Garnacho had cancelled out Sandro Tonali's opener against the run of play to ensure parity for the visitors at half-time.

But Harvey Barnes turned in Jacob Murphy's cross four minutes into the second period to spark a United collapse.

Barnes galloped through the Red Devils defence to fire his second into the top corner just after the hour mark.

Ruben Amorim had left out under-fire goalkeeper Andre Onana after two errors in Thursday's 2-2 Europa League draw at Lyon followed a war of words with former United midfielder Nemanja Matic.

Stand-in Altay Bayindir did his case for future selection no favours for the fourth goal as his clearance went straight to Joelinton, who headed down for Bruno Guimaraes to slot home.

Newcastle's fifth consecutive win takes them to within one point of third-placed Nottingham Forest, with a game in hand. United slip to 14th.