51′ More good play from Adan
Vieira breaks forward to pounce on a through ball but Adan sees the danger and gets there first.
The Sporting keeper has been really impressive this evening.
48′ Good chance for Martinelli
Zinchenko plays a clever ball into the box to play in Martinelli on the left.
He goes for the chip but Adan makes himself big and does well to block it behind for a corner.
Vieira hits one from just outside the area shortly afterwards but it flies just wide.
47′ Strong start to the half from Sporting
Arsenal give the ball away and Sporting work a couple of nice chances at the edge of the box.
Turner deals with them both comfortably but it continues to be an uncharacteristically loose performance at the back from the Gunners
Paulinho puts the home side in front!
That was against the run of play after Sporting had been on the back foot for the start of this half.
A nice move from the home side works the ball into the box and they get a chance on the right. Turner does well to save the initial shot, but Paulinho is unopposed and fires in the rebound.
Arsenal now have it all to do in this first leg.