Costa and Felix score but Morata sent off in Atletico win
Costa headed in on 26 minutes at the Iberostar Stadium and Felix struck again after half-time to set Atletico on their way before Alvaro Morata was sent off just eight minutes after being brought on as a substitute. Morata's punishment will be to miss Atletico's city derby on Saturday against Real Madrid at the Wanda Metropolitano, which could be a contest of first against second in La Liga.
Atletico sit top of the table on 13 points but Real could overtake them by beating Osasuna later on Wednesday. Athletic Bilbao are one point behind in second place after preserving their unbeaten start to the season with a 1-1 draw at Leganes.
Diego Simeone's Atletico appear at least to have put behind them a sticky patch that included two draws and a defeat in three games, even if one of those draws was their thrilling comeback against Juventus in the Champions League.
But familiar concerns had returned about Atletico's threat in attack, with Costa failing to score in any of their opening six matches while offering limited service to the 19-year-old Felix, who has shown glimpses of his undeniable talent but is also still adjusting after his summer move from Benfica.
Goals for both will have been welcome even against a Mallorca side that now sit 17th, having conceded the joint most goals in the division so far. Given Morata's red card, Costa and Felix are also almost certain to join forces again for the visit of Madrid this weekend.
Costa's goal was simple, as Mallorca failed to clear Koke's cross from the right and the striker nipped in to head past goalkeeper Manolo Reina. Felix's was more complex but owed something to fortune too. The Portuguese did brilliantly to bring a looping ball down in the area but his finish on the turn took a cruel deflection before spinning up and into the far corner.
The only blot on Atletico's night came from Morata, who was booked twice in two minutes of madness after an argument with Mallorca's Xisco Campos. Morata had come on in the 69th minute and was walking towards the tunnel in the 77th.