The Cottagers defender helped Dele Alli’s effort into his own net midway through the first half for what proved to be the only goal of the game, though Josh Maja had a second half strike ruled out for handball in the build-up.
Jose Mourinho gave Dele Alli his first league start since the opening day of the season as part of a new-look front four alongside Gareth Bale, Harry Kane and Heung-min Son.
Bale, Son and Dele were all involved in the opener, the Korean’s low cross flicked towards the far corner by Dele but seemingly heading wide until a crucial touch from Tosin poked it into an empty net.
Spurs had been on top in the first half but the hosts were much the better side after the break, with Mourinho’s side once again failing to put a game to bed after taking an early lead.
That trait had cost them in the reverse fixture and looked to have done so again here when Maja swivelled to fire home but VAR intervened, following the letter of the law to adjudge that Mario Lemina had handled in the build-up, despite his arm being by his side when it had the ball kicked into it from close-range by Davinson Sanchez.