Barcelona's Neymar and Lionel Messi (L) celebrate a goal against Real Sociedad during their Spanish First division soccer league match at Camp Nou stadium in Barcelona, Sept 24, 2013. [Photo/Agencies]

Very happy

"I am very happy with my first goal in La Liga but the most important thing was the victory," Neymar said in a pitchside interview with Spanish television broadcaster Canal Plus.

"We are playing well, each day better," added the 21-year-old, whose assist for Messi was his third for the Argentine in the league this season.

Martino has been alternately resting some of his key players in the early stages of the season and Messi, who almost always plays a full match, was replaced with 10 minutes left.

He looked less than pleased with the decision but later posted a message on his Facebook page explaining that although he doesn't like to be substituted it's best for the team.

Atletico coach Diego Simeone has transformed the team since taking over at the end of 2011 and their success this season has in large measure been down to Costa's excellent form.

The combative Brazilian opened the scoring in the 18th minute at the Calderon, sidefooting Juanfran's cross past Osasuna goalkeeper Andres Fernandez, and made it 2-0 seven minutes later with a powerful header from Koke's centre.

Oriol Riera stole in to volley past Thibaut Courtois shortly before halftime but Atletico comfortably held on to their lead to secure a morale-boosting win ahead of Saturday's derby at Real's Bernabeu stadium.

In Tuesday's other games, Malaga won 2-0 at home to promoted Almeria to climb to seventh on eight points and Levante drew 1-1 against visiting Real Valladolid.