Valverde thundered a right-footed shot into the 27th-minute from the edge of the Girona box, but Argentine goalkeeper Gazzaniga produced a superb save.
Icheveri then threatened to break the deadlock a minute before half-time, beating Camavinga with a sharp dribble inside the box before slipping as he shot; the ball still flashed just wide of the post.
Valverde finally broke the deadlock in the 51st minute, collecting a pass from Díaz on the edge of the box and firing an unstoppable shot that Gazaniga could only push into the net.
Vinícius nearly doubled the lead in the 57th minute, collecting the ball on the right of the box, cutting inside, and firing a low shot that Gazaniga saved brilliantly.