© Getty Images
Costa doubled Atletico's advantage in the 25th minute, this time heading home an Arda Turan cross.
Oriol Riera was the man who gave Osasuna some hopes of a comeback in the second half as he turned home Sisi's free kick on the stroke of half time.
However, it was hosts Atletico who were in control of possession in the opening minutes after the restart, although Javi Gracia's side did have a chance on 64 minutes.
On that occasion Emiliano Armenteros capitalised on a mistake from Miranda, advanced on goal and shot wide from close range.
Los Rojillos failed to create anything of note thereafter as Atletico cruised for the remainder of the match to bag maximum points and make it six wins out of six in La Liga.