ATLÉTICO 1 - RAYO 0
Griezmann keeps Atleti in hunt
The substitute had an immediate impact as his goal beat Rayo to keep up the pressure on leaders Barça, who defeated Betis later in the day.
Atlético Madrid saw off Rayo Vallecano on Saturday to keep up the pressure on leaders Barcelona, who beat Real Betis later in the day to stay top.
Coach Diego Simeone made seven changes to the team that beat Bayern Munich 1-0 on Wednesday, with only keeper Jan Oblak, Jose Giménez, Gabi and Juanfran keeping their places.
Simeone was serving the first of a three-game touchline ban and watched his side struggle to break down Rayo.
The hosts created only one clear chance before the break, a low shot from Angel Correa that was superbly tipped away by Rayo goalkeeper Juan Carlos.
Atlético's top scorer Griezmann was brought on along with Fernando Torres in the 54th minute and needed less than 60 seconds to have an impact.
The France striker pounced on a loose ball on the edge of the area and, with his next touch, smashed it high into the net, his first goal in five games in all competitions.
Torres squandered a chance to seal the win and Rayo nearly punished Atlético, who were relieved to see striker Javi Guerra head over the bar after appearing unmarked in the box.