Thomas Partey's volley shortly after half-time was enough to give Atletico their ninth straight win in all competitions.

Reus goalkeeper Edgar Badia saved three shots from Fernando Torres in the first half as the third-tier Catalan outfit frustrated their in-form opponents, while Koke hit the post with a free-kick.

Lucas Hernandez had a goal chalked off for handball against Stefan Savic early in the second half, but Atleti were soon ahead thanks to a placed 22-yard strike from Thomas.

All eyes were on Diego Simeone, who has emerged as one of the leading candidates to succeed Jose Mourinho at Chelsea after the Portuguese coach left Stamford Bridge by mutual consent on Thursday following the defending Premier League champions' poor start to the season.

Simeone handed Torres another chance to score his 100th Atletico goal, with the striker replacing Luciano Vietto in the only change to the Atleti team from the first leg.

Atletico dominated the early exchanges but took 16 minutes to create their first opening.

Thomas slipped in Jesus Gamez on the overlap and the defender picked out an unmarked Torres in the box, but the Spain striker hit his shot straight at Badia in the Reus goal.

The hosts, leading 2-1 from the opening leg, came even closer to the first goal when Badia kept out a firm header from Torres, with the rebound bouncing harmlessly wide off Savic.

Plenty of opportunities were falling for Torres, with the striker seeking to break a 15-match dry spell to finally reach his landmark.

On the half-hour he again got free in the box but could only pick out Badia with an improvised finish, before Koke hit the post with a cross-cum-shot from a free kick.

Reus were causing problems on the break as well as frustrating Atletico with their determined defending, with Ricardo Vaz forcing a save from Miguel Moya just five minutes before half-time.

Hernandez had the ball in the net shortly after the break, but the goal was disallowed for a handball against Savic and the opening goal finally arrived on 53 minutes.

Guilherme Siqueira's left-wing cross was cleared straight to Thomas, who found the bottom corner with a cushioned volley from 22 yards.

Reus pressed for a goal to get them back in the tie with Angel Martinez testing Moya with a 25-yard drive, before Alex Colorado put a free-kick over the bar from a good position with 10 minutes to go.

Torres had another late chance to finally achieve his 100th Atletico goal but missed the target from a great position.