Arsenal made a positive start at the Ramon Sanchez Pizjuán as Takehiro Tomiyasu fired wide with the first shot in anger before Martinelli saw his effort kept out by the onrushing Orjan Nyland.
After seeing his side put under some early pressure, new Sevilla boss Diego Alonso would have been pleased to see his side carve out an opportunity in the 10th minute.
Jesus Navas, who started in Sevilla’s meeting with Arsenal back in 2007, sent a low cross in at the near post for Lucas Ocampos to attack, but the Argentine could only steer the ball wide.
Following those entertaining opening exchanges, the opportunities began to dry up as the first period descended into a cagey affair.
However, the contest suddenly burst back into life in first-half stoppage time when Arsenal broke away through Martinelli, who rounded the goalkeeper and calmly slotted home to send the visitors into the break in a jubilant mood.
Having carried significant momentum into half-time, Mikel Arteta's side surged out of the blocks in the second period. Martin Odegaard blazed over from a promising position after Jesus was denied by the sprawling Nyland.
As it proved, the Gunners only had to wait a few more minutes for their second goal when Jesus drifted inside, before curling an unstoppable effort into the far corner.
After coming from two goals down to draw with Chelsea at the weekend, Arsenal were firmly aware that their lead was a precarious one. Sevilla attempted to ignite their own comeback just before the hour mark as Nemanja Gudelj powered a header home from Ivan Rakitic's out-swinging corner.
Unlike Arsenal at Stamford Bridge, the Spanish side were unable to complete the fightback, ensuring Alonso’s first Champions League game as manager ended in defeat. While Arsenal move onto six points, the Andalusians are four points adrift in third position.
Flashscore Man of the Match: Gabriel Jesus (Arsenal)
Click here to see all the stats from the match.
Lens and PSV can’t be separated
In the evening's other Group B match, Lens Came back to secure a draw at home against PSV and maintain their grip on second place in the standings.
You see all the stats and read a full report here.
