Both Thomas Frank and Mikel Arteta named strong sides for the game at a packed Kai Tak Stadium but it was Spurs who proved the far more cohesive unit during the first half.
The Europa League winners hit the post three times in total, with Pedro Porro and Mohammed Kudus both striking the upright directly from corners that left David Raya flapping at thin air. The impressive Wilson Odobert also saw a low effort deflected onto the post after the ball had rebounded into his path on the left-hand side of the area.
Frank's team were, thus, good value for what proved the game's only goal, which came courtesy of Sarr, who sensationally chipped a stranded Raya from the halfway line, after Myles Lewis-Skelly had been caught in possession by Richarlison.
Arsenal improved after the break but Kai Havertz and Gabriel Martinelli wasted decent shooting opportunities, while Gyokeres didn't really get a sniff of goal after coming on for the final 15 minutes, and it was Spurs who actually went closest to scoring, when Mickey van de Ven sent a back-post header just wide after good work on the right wing from Mathys Tel.