Dele Alli, Eric Dier and Heung-min Son were all on target in the first half as Spurs swatted the Hornets aside.
Son added another after the interval, allowing Mauricio Pochettino to ease Harry Kane back into action for the final half an hour as Spurs claimed an 11th straight victory on home turf.
The 23-year-old's early return from injury represents a huge boost and on this evidence, Spurs will surely push their rivals all the way in the title race.
Yet questions were asked of the north Londoners early on, with Stefano Okaka proving to be a particular nuisance, but Hugo Lloris showed bravery to clear a high ball ahead of the Italian.
It did not take long for Spurs to create a chance of their own when Christian Eriksen picked out Vincent Janssen, who rolled his marker before seeing his low effort kept out by Heurelho Gomes.
Another chance went begging for the Dutchman as he somehow managed to deflect Kieran Trippier's first-time cross onto the bar from a couple of yards out.
Alli, however, did not require a second invitation to find the net when he curled home his 15th league goal of the season to put Spurs in front.
The 20-year-old's sublime strike gave Gomes no chance, with the Brazilian little more than a spectator.
Watford were undone again just six minutes later when Son's effort deflected into the path of Dier, who kept his head to produce a measured finish.
The visitors were dead in the water when Son burst forward to take advantage of some poor defensive pressing and rifle a left-footed drive into the bottom corner.
The animated Walter Mazzarri must have had some choice words for his side at the break but they had little effect.
Jan Vertonghen threatened to end his goal drought when he emerged as a surprise leader of a counter attack, but the Belgian's touch let him down at the opportune moment.
The same could not be said of Son a minute later when the South Korean grabbed his second goal by meeting Kieran Trippier's deep cross with an excellent first-time finish.
With the game over as a contest, Pochettino called for Kane on the hour mark. The striker - understandably - did not appear to be firing on all cylinders, having injured his ankle ligaments less than a month ago.
But he was still sharp enough to collect Trippier's quick free-kick before seeing his effort cleared off the goalline while only the width of the crossbar denied Kane in injury time.
Watford are heading towards a respectable mid-table finish. But Spurs go marching on and obscurity is certainly not on the cards for Pochettino's side as they continue to put pressure on Chelsea.