The 1-0 win at the Wanda Metropolitano secured a 2-1 aggregate passage over Arsenal, denying the Gunners their final chance at silverware in manager Arsene Wenger's final season at the helm.

With the upper hand following last week's 1-1 first-leg draw in London, Atletico never looked troubled on the night. Costa's goal from Antoine Griezmann's assist just before the break was enough to progress against an Arsenal team which had a lot of the ball but created few chances.

Costa did not play at all in the first half of the season due to a FIFA transfer ban and had not scored since February having been hampered by a hamstring problem. But the Atletico coach told his postgame news conference that these type of big occasions were precisely why they had brought the Brazil-born Spain international back to the club.

"Costa came for this, to be important for the team, in games like this," Simeone said. "The team needed a forward with his rage, his intensity, the mistakes he provokes in opponents. Along with the other forwards we have, that was very important."

Granit Xhaka's 20-yard shot early was the only save for Atletico goalkeeper Jan Oblak over the 90 minutes, while Griezmann, Costa again and Koke all came close to adding another for the home side.

"We were able to stop their counter-attacks, where they are most dangerous," Simeone said. "The team suffered little, and had chances to make the score a bit wider."

Simeone has now guided Atletico to a fourth European final in seven seasons in charge. But the Argentine deflected praise onto his large group of collaborators, including assistant German "Mono" Burgos who had replaced him on the line during the game, and also came to the news conference afterwards.

"I'm the visible head of a group who have worked here in an extraordinary way for six years, many people working every day so things go in a positive way," Simeone said. "There is a loyalty here that is very difficult to find.

"The club counted on us in the moment, and we keep giving our best. Stopping to think all we are doing is not good, we need to look at Espanyol, our game on Sunday, and stay second in La Liga, which is very important for us."

Simeone said he was expecting a difficult test in the final in Lyon on May 16, against a Marseille team who battled through in extra-time at Red Bull Salzburg in Thursday's other semifinal.

"This was an important step tonight, but obviously hoping for something better to come," he said. "Marseille are a difficult team, they came through a difficult game tonight, for sure it will be a great final. This is a big step, but the most important one is still to come on May [16]. And we are really looking forward to that."

There were smiles when one reporter asked if the best thing about this year's final was that his team would not have to face their 2014 and 2016 UCL conquerors Real Madrid.

"They are not in this tournament, so the question is cancelled," Simeone replied with a grin.