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The visitors tested Spurs in the early stages, as they powered forward on every occasion and forced several errors by the home side.
Ba then swivelled in the area in the 12th minute before powering a shot towards goal, which cannoned off the Spurs post.
The young striker was able to power forward to the edge of the box blast a shot off the foot of the post and into the net.
Besiktas were unlucky not to equalise in the latter stages of the first half, as Ba and Tomas Sivok threatened time after time, while Olcay Sahan had to be denied by Hugo Lloris's outstretched foot in the 32nd minute.
The game continued to be open-ended after the break, as Andros Townsend curled a shot over the bar in the 54th minute, while moments later, Sahan's shot had to be thwarted by a one-handed Lloris save.
Just before the hour, Bentaleb's low, drilled effort skimmed narrowly past the far post, but Sahan countered again a few minutes later when his acrobatic scissor kick flew narrowly wide.
As Besiktas turned the screw in the latter stages of the game, Lloris was forced to deny the visitors' frontline time and time again, with a multitude of saves to keep Spurs in the lead.
Just when it seemed like the home side would claim all three points, a Vlad Chiriches handball in the final minute of the game gifted the visitors a penalty, with Ba making no mistake and nonchalantly stroking the ball past Lloris into the net.