Walcott struck with 50 minutes on the clock, firing home to settle a dreary encounter at Goodison Park, denying Rafa Benítez’s men what would have been a fifth consecutive Premier League victory on the Spaniard’s 100th game in charge.
In all, it was a disappointing evening for Newcastle, who hadn’t been beaten since their last visit to Merseyside - where they faced Liverpool at the start of March - going into this fixture.
An uneventful first period saw few clear-cut opportunities created by either side. After Cenk Tosun sliced one wide when Walcott’s run was halted in the box, United grew into the contest, with debutant Islam Slimani troubling the Toffees’ centre half pairing of Michael Keane and Phil Jagielka with his movement.
Yannick Bolasie saw his effort blocked by Jamaal Lascelles midway through the half but it wasn’t until after the half hour mark that a real chance presented itself. Wayne Rooney’s high, hanging cross was nodded across goal by Keane, but Jagielka couldn’t steer it in as he volleyed over at full stretch.
It was the visitors, though, who carved out the first opening after the restart. Kenedy’s lofted pass released Ayoze Pérez but, under pressure from Keane, the Spaniard could only drag his shot wide of the target with his unfavoured left foot.
And just a matter of seconds later, with the half barely five minutes old, the Toffees broke the deadlock. It came following a deep Bolasie cross, which Newcastle couldn’t clear. The ball fell at the feet of Walcott, who was able to cut inside and lash his side’s opener into the roof of Martin Dúbravka’s net.
With just over an hour gone, Benítez introduced Dwight Gayle in place of Slimani, and the frontman’s first touch almost brought an equaliser. Jamaal Lascelles glanced on Matt Ritchie’s corner but Gayle, at the far post, volleyed just over Jordan Pickford’s crossbar.
Kenedy then sent over an inviting cross for Pérez, but his flick was comfortably held by Pickford. Defender Keane went in the book for upending Gayle on the edge of the area, with United firmly in the ascendency going into the final 15 minutes.
But Ritchie’s clipped effort from the resulting effort just cleared the bar, and despite plenty of late endeavour after the introductions of Jacob Murphy and Mikel Merino, the Magpies tasted defeat for the first time since the loss at Anfield on 3rd March.
