Cenk Tosun scored the only goal of the game as Mauricio Pochettino’s side fell to second place in Group C.
It was a mediocre result for the Londoners against a team who started with only 14 first-team players available.
It was all Tottenham in the first seven minutes prior to the first of two floodlight failures, but it wasn’t until play had re-started that the visitors created the first chance, after 15 minutes. Roberto Soldado failed to make good contact with a Younes Kaboul nod down and saw his tame effort easily saved.
Soldado’s lack of confidence was visible again just ten minutes later. Mousa Dembele, who looked dangerous in a high role, played a tidy ball forward for the Spaniard, but his shot was easily blocked.
The visitors managed to get the ball in the back of the net in the 26th minute via Nacer Chadli, but the referee rightly called for offside.
Tosun then hit the crossbar, but Spurs didn’t heed the warning, because the same player gave Besiktas the lead in the 59th minute by converting Olcay Sahan’s low cross.
Conceding the goal seemed to jolt life back into Spurs, but once again Soldado couldn’t convert another good chance.
Kerim Frei then had a great opportunity to double the lead for Besiktas in the 67th minute, but he sent his shot wide.
Pochettino made changes by sending Erik Lamela on for Soldado and Aaron Lennon on for Paulinho as he attempted to snatch a point that would secure top spot in the group, but it was the Turkish side that continued to look more dangerous.
Olcay ?ahan send a shot wide with ten minutes to go, before Michel Vorm saved from At?nç Nukan five minutes later.
It looked like the drama was all over, until the lights went out again at the beginning of three minutes of injury time. After a short delay play was resumed, but Tottenham were unable to force a leveller.