The two sides hadn't met on Gallowgate for a decade and, roared on by an expectant crowd, the Magpies started on the front foot at St. James' Park as they looked to make it three Premier League wins in a row at the expense of their local rivals.
In the third minute, boyhood Magpies fan Lewis Hall sent over a wonderful cross from the left and Anthony Elanga, fresh from his two midweek goals at Camp Nou in midweek, arrived with a powerful header which flew just over the bar at the Leazes End.
Then in the tenth minute, Nick Woltemade seized upon a loose pass from Luke O'Nien to win the ball high up the pitch and fed Gordon, who advanced and drilled unerringly beyond Melker Ellborg for his 17th goal of the season - and his biggest of them all.
As the Black Cats looked to respond, Aaron Ramsdale flew across his goal in the 24th minute to prevent Chemsdine Talbi's long-range strike from finding the top corner. The resulting flag kick was half cleared by United, as far Chris Rigg, whose shot was well off target.
Elanga shot into the side-netting after popping up on the left then, in the 43rd minute, Hall centred from the left once more but Sven Botman's looping header rebounded back off the far post.
A Hall free-kick was gathered by Ellborg in first-half stoppage time.
Sandro Tonali missed out through injury - Woltemade took his place in midfield - while Botman came in for Malick Thiaw.
United's starting XI included two Newcastle supporters in Dan Burn and Hall, with another two - Jacob Murphy and Sean Neave - among the substitutes.
**Newcastle United:** Aaron Ramsdale, Kieran Trippier (c), Lewis Hall, Sven Botman, Joelinton, Anthony Gordon, Harvey Barnes, Anthony Elanga, Nick Woltemade, Dan Burn, Jacob Ramsey
**Subs not used:** Nick Pope, Yoane Wissa, Malick Thiaw, William Osula, Tino Livramento, Jacob Murphy, Joe Willock, Alex Murphy, Sean Neave