Atletico's first goal of 2018 came against the run of play, just after the half-hour mark, when Diego Godin headed his first goal of the season from Yannick Carrasco's flighted free kick.

Their second came four minutes later when a sweeping counter-attack saw Kevin Gameiro set up strike partner Fernando Torres to knock home at the back post [albeit while offside].

Having been forced by a FIFA transfer ban to sit out the first half of the season following his €66 million return from Chelsea last summer, Costa entered early in the second half and within five minutes had finished smartly at the near post from Juanfran's cross.

The Brazil-born Spain international appeared to hurt his right knee in scoring, and received lengthy treatment on the sidelines, although he played on to see another sub, Antoine Griezmann, finished the scoring with a deflected free kick in added time.

The rojiblanco coach told the postgame news conference that both Costa and fellow debutant Vitolo, a €36 million summer signing from Sevilla, were "status" players who he hoped would now quickly find their best form.

"I am taking a lot more from the game than Costa's goal and the fright," Simeone said. "The team played a very good game against a side that competed well and started very strongly.

"Costa's entrance lifted our spirits. Diego gives us pace, strength, commitment ... what we expect from him. He showed all that in those first five minutes. [His] goal was a very direct counter-attack. Vitolo must get involved with the needs of the team, bit by bit. He also entered very well. They are two players with status, and I hope they can reach their best form as soon as possible. Luckily we have many games coming up, which makes it easier for us to give them playing time."

Simeone pointedly praised the contribution made by starting strike pair Gameiro and Torres -- two forwards whose playing time is likely to be threatened in the coming weeks by the new arrivals.

"We must remain relaxed, as extremes are bad," he said. "But Torres and Gameiro also responded very well. The team did well in a tough game, which is what makes me happiest."

Next up for Atletico is Saturday lunchtime's La Liga game at home to Getafe, followed by next Tuesday's return at the Wanda Metropolitano.