Chelsea remain in sixth place in the standings but still have a game in hand, while Spurs now find themselves nine points adrift of leaders Liverpool.
Sarri made the decision to drop Kepa Arrizabalaga after his refusal to be substituted during the EFL Cup final, but replacement Willy Caballero had little to do as Chelsea dominated the opening exchanges.
The first opportunity arrived at the feet of Gonzalo Higuain, but the Juventus loanee could only strike the post with his 14-yard volley after Spurs had failed to deal with a cross.
Spurs eventually warmed into the contest and Chelsea needed to make a number of timely blocks at the back, but the visitors almost broke the deadlock just before the half-time whistle.
Harry Winks was set up around 25 yards from goal, and the England international's dipping strike beat Caballero and struck the centre of the crossbar.
Chelsea returned for the restart with the intention of going onto the front foot and while that turned out to be the case, they continued to struggle to create openings in the final third.
However, Sarri's side soon went ahead with the first shot on target. Pedro got in behind the Spurs defence and capitalised on a poor attempt at a tackle from Toby Alderweireld before drilling a low shot through the legs of Lloris from close range.
Spurs wasted little time in going on the front foot and Harry Kane should have done better when meeting a cross from Ben Davies, but the forward miscued a volley wide of the post after seemingly being distracted by Erik Lamela.
Alderweireld then headed well wide of the far post after getting on the end of a Christian Eriksen corner, but the visitors were unable to build on that spell of pressure as Chelsea began to sit deep.
Much of the closing quarter passed by without incident, but Spurs gifted Chelsea a match-clinching second with six minutes remaining when a mix-up between Trippier and Lloris led to the right-back passing the ball into his own net from 20 yards out.
The goal effectively ended the game as a contest and while Sarri would have been left encouraged by a second successive strong showing from his players, Mauricio Pochettino will acknowledge that his team have work to do just to stay in the top four.
CHELSEA (4-3-3): Caballero; Azpilicueta, Rudiger, Luiz, Alonso; Kante, Jorginho, Kovacic (Loftus-Cheek 77'); Pedro, Higuain (Giroud 84'), Hazard (Willian 60')
TOTTENHAM HOTSPUR (4-4-2): Lloris; Trippier, Alderweireld, Sanchez, Davies; Winks, Sissoko (Rose 85'), Eriksen, Lamela (Llorente 70'); Son (Lucas Moura 80'), Kane