Tottenham, against the spiralling pre-match odds, took the lead inside four minutes. After Timo Werner inexplicably misplaced a short corner-kick routine, Spurs worked the ball back upfield with confidence to Pedro Porro on the right flank, and his cross perfectly landed on the head of Dominic Solanke, who directed it into the bottom corner beyond Martin Dubravka.
However, their lead didn't last very long. Lucas Bergvall tried to dribble his way out of trouble but was stopped by Joelinton, whose hand struck the ball when winning possession back. Anthony Gordon was then slipped in to finish past debutant goalkeeper Brandon Austin, with the home bench furious the goal was allowed to stand with no handball call.
Newcastle went ahead just before half-time when Jacob Murphy scampered to the byline and cut a cross back for Alexander Isak, who had escaped the marking of Radu Dragusin, to tap in at the far post, notching up his ninth goal in his last seven games.
Dragusin was taken off at the break and replaced by Sergio Reguilon, meaning Tottenham played the second half without a recognised centre-back, with midfielder Archie Gray and full-back Djed Spence filling in.
A spirited Spurs pushed forth in search of a leveller and rattled the post through Brennan Johnson shortly after the interval, while Gordon blazed over at the other end following a swift breakaway. Gordon was also denied a penalty when his face bounced off the shoulder of Dejan Kulusevski, leaving him bloodied and requiring several minutes of treatment on the pitch.
James Maddison, on from the bench, went close to bringing the scores even again when his whistled shot from wide left flew round the post, while Johnson and Reguilon both flashed efforts across the face of goal shortly afterwards. Deep into 10 minutes of added time, Solanke forced one last save out of Dubravka with another header.
That was as close as Tottenham came to rescuing a point and Newcastle held off their advances for the victory. Spurs remain 11th in the Premier League standings, while the Magpies are up to fifth.