Steve Bruce's side deservedly led 2-1 at half-time after goals from Callum Wilson and Jacob Murphy.
However, the Magpies fell apart after the break. Said Benrahma equalised, Tomas Soucek’s followed up Michail Antonio’s saved penalty before the latter added a fourth.
Our writer Jordan Cronin was at St James’s Park – and here’s how he rated each Newcastle player:
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9. Miguel Almiron - 6
You know what you get from Almiron now. Lots of hard work and energy. Was denied a goal by the crossbar in the first-half. Photo: Stu Forster
10. Callum Wilson - 7
Was great to see United’s new number nine on the scoresheet. He marshalled the West Ham defenders well but faded when Newcastle’s backs were against the wall. Photo: Charlotte Tattersall
11. Allan Saint-Maximin - 7
A rare 90 minutes for Saint-Maximin. His work for Wilson’s opener was world-class. The Frenchman is always United’s best bet of a breakthrough. Photo: Charlotte Tattersall
12. Ryan Fraser (on for Shelvey, 70) - 5
The Scotland international struck narrowly past Fabianski’s far post late on. Photo: Michael Regan