What you need to know:
- Morata thumped home his fifth league goal of the season just before the hour mark to put Atletico in front in Madrid
- The 27-year-old also set up Angel Correa to level the scores in first-half stoppage time as he continued his superb recent form
- Koke rounded off the victory in added time when he collected Diego Costa's low cross to slot the third past Espanyol goalkeeper Diego Lopez
Alvaro Morata hit his sixth goal in as many games in all competitions as Atletico Madrid moved third in La Liga with a 3-1 win over struggling Espanyol on Sunday, while Sevilla kept pace thanks to a derby win over fierce local rivals Real Betis.
Morata thumped home his fifth league goal of the season just before the hour mark to put Atletico in front in Madrid after Sergi Darder had shocked the Wanda Metropolitano with fine opener seven minutes before the break.
The 27-year-old also set up Angel Correa to level the scores in first-half stoppage time as he continued his superb recent form which has seen him find his shooting boots after not scoring since the first game of the season.
"The important thing is that we won. I always say it, in the end it's about being all together," said Morata.
Koke rounded off the victory in added time when he collected Diego Costa's low cross to slot the third past Espanyol goalkeeper Diego Lopez.
Diego Simeone's side stay just a point behind Barcelona and Real Madrid, easy winners over Eibar and Celta Vigo respectively on Saturday, but move above Real Sociedad, who drew 1-1 with Leganes on Friday.
Atletico were expected to challenge for the title this season after signing teen prodigy Joao Felix in the summer, and they are in the mix despite a spotty opening three months of the season that has seen them lose only once but draw six of their 13 league matches.
They are also close to qualification for the Champions League knockout stages, as they are second in Group D, three points behind leaders Juventus.
"We are a strong group and we are not affected by what is said about us. If we do what we have to do, we will go far this year," Morata added.
Espanyol meanwhile stay second-from-bottom after their third league defeat on the bounce, adding to a dismal domestic run that has seen them win just once since mid-September.
Atletico are joined on 24 points by Sevilla, who moved up to fourth after beating Real Betis 2-1 thanks to Luuk de Jong's strike which won a tense Seville derby.
Dutch international De Jong struck the winner 10 minutes after the break to grab his second goal of the season and leaves Sevilla's city rivals languishing in 17th place, four points above the relegation zone.
Lucas Ocampos gave Sevilla the lead in the 13th minute when he latched on a weak clearance and lashed home a low drive.
The hosts levelled just before the break through Loren Moron, who pounced on Emerson's header to tap in from close range.
However De Jong hit the winner to silence the partisan home crowd not long after the restart, his fierce near-post finish just about enough to ensure the three points and keep them in touch with the big two.