The Mexican striker produced two clinical finishes to set the Magpies on their way to a first defeat in five outings, though – in between – Rafa Benítez’s side wasted a string of opportunities to draw level.
They were flattened by Hernández’s second, though, and Felipe Anderson’s strike – with virtually the last kick of the game – added a touch of gloss to the scoreline for West Ham.
Though the game started in open manner, neither team were able to create anything clear cut prior to the Hammers taking an 11th-minute lead. Robert Snodgrass whipped in a cross from the right flank, and Hernández had the time and space to judge the flight of the ball before sweeping home from a central position.
United were afforded the chance to equalise from a very similar move less than five minutes later. Defender Fabian Schär provided the delivery, but Ayoze Pérez got the ball stuck at his feet and failed to test goalkeeper Łukasz Fabiański.
Pérez squandered two more opportunities to restore parity prior to the half-hour mark. The Spaniard nodded Matt Ritchie’s free kick straight at Fabiański after Javier Manquillo was fouled on the left, before heading high of the target from the winger’s corner after finding another pocket of space inside the penalty area.
The Magpies looked the more likely to strike next leading up to the break, with Kenedy and Pérez both getting efforts away and West Ham’s Pablo Zabaleta forced to make a last-gasp challenge on Salomón Rondón with the Venezuelan bearing down on goal.
Another Hammers defender, Aaron Cresswell, produced a similar challenge to deny Rondón early into the second half, with the frontman having taken down a left-wing cross from Kenedy before taking aim. Two minutes later, Rondón powered a header past the near post as the Magpies continued to push.
At the other end, Hernández just failed to get on the end of Marko Arnautović’s square after a neat Hammers move. The Mexican had another sight of goal less than a minute later, controlling Felipe Anderson’s threaded pass before curling the ball into the side netting with his left foot.
However, shortly after the hour mark, the Magpies’ defence allowed Hernández in again – and this time, he took his chance. Arnautović flicked a lofted ball over the top of the backline and into the path of the forward, who duly continued his run before producing a confident finish past Martin Dúbrvaka.
United’s Slovakian stopper managed to prevent further damage after 68 minutes, getting his body in the way of Felipe Anderson’s strike after the Hammers broke at pace down the Magpies’ vulnerable right-hand side. From the resultant corner, Issa Diop guided Snodgrass’ delivery narrowly wide of the far post.
With the clock ticking, Benítez opted to pair another out-and-out striker with Rondón, taking Pérez off for Joselu. However, it was the Venezuelan who continued to look the most likely to pull a goal back for Newcastle, bringing a decent stop out of Fabiański after meeting Christian Atsu’s knock-down.
In truth, however, United rarely looked like troubling the Hammers’ clean sheet. Instead, it was Manuel Pellegrini’s side who had the final say, with Felipe Anderson again enjoying the freedom of the Magpies’ right before smashing the ball past a helpless Dúbravka.
