Much of the first half was played in Newcastle territory but Spurs failed to find a way through their opponents before the away side grabbed a surprise lead in the 39th minute through Fabian Schar, who drilled home a low free kick past Hugo Lloris.
Newcastle’s lead, however, lasted only four minutes when Ben Davies got ahead of his marker to meet a delightful Son cross to level the game and bring to life a dour half that had initially promised little.
Spurs hit the front almost immediately after the restart when wing back Doherty scored with a diving header from a dangerous Harry Kane cross before Son doubled the their advantage in the 54th minute as he finished off a sweeping team move.
Newcastle made a double switch just before the hour-mark, bringing on Jacob Murphy and Bruno Guimaraes, but Spurs heaped more misery on the visitors as Emerson and substitute Bergwijn added two more goals to complete the rout.
Spurs are now level on 54 points with Arsenal but their north London neighbours can leapfrog them back into fourth place when they travel to Crystal Palace on Monday. Newcastle are 15th with 31 points, nine clear of the relegation zone.