Mauricio Pochettino was forced to make several changes to the team that beat Spanish champions Real Madrid in midweek, Dele Alli missing with a hamstring injury as Spurs looked to put an end to a dismal run of London derbies at a sun-drentched Wembley Stadium.
A minute's silence was observed for Remembrance Sunday before the game got underway and Crystal Palace began to cause trouble for Spurs at the back. Paulo Gazzaniga, making his first Premier League appearance in two years, looked nervy as he raced off his line to collect a cross and missed the ball as he crashed into Sakho three minutes in. After the final whistle, his performance earned praise.
The visitors had made a confident start, but Tottenham gradually pushed them back and settled on the ball. Sakho's impressive exploits as he led the Palace back line helped them keep the home side at bay, with pacey wing-backs Danny Rose and Serge Aurier heavily involved in Tottenham's surges forward.
Pochettino opted to play a high defensive line, giving Zaha the space to run in behind, but Eric Dier was on his toes to deny the Ivorian forward with two sensationally timed last-ditch clearances.
The hosts looked sluggish at times with Palace concentrated at the back and always ready to break with pace. A similarly lethargic start to the second half almost saw them go behind when Aurier lost focus and gifted the ball straight to Andros Townsend. The former Tottenham winger surged forward before firing a low strike across goal Gazzaniga did well to palm away for a corner.
The close call prompted Pochettino's men to search for an opener with more determination and they earned a succession of corners as a period of sustained pressure on Speroni's goal ensued. Aurier again gave the ball away inexplicably in midfield and Townsend released Zaha on goal. Gazzaniga raced off his line and the forward rounded him easily before somehow dragging his shot across goal and wide of the gaping target.
Gazzaniga then showed great reactions to keep out Milivojevic's header from close range, and the visitors were made to pay for their missed chances. A scramble with several deflctions ended up with the ball ricocheting into the path of Son, who lifted up his head and sent a composed curling effort into the bottom corner from just outside the area.
The goal took Palace by surprise just as they were getting into their stride, but they continued to break upfield and pose a threat on Gazzaniga's goal, while slightly neglacting their defensive duties. This granted Son accres of space as he received Vertonghen's pass and with only the keeper to beat he rippled the side-netting.
Tottenham finally came away with a 1-0 win thanks to Son's second-half strike, while further increasing Crystal Palace's woes. Roy Hodgson's side, who deserved more, are still bottom and five points from safety.