Angola striker Manucho netted the game's only goal within five minutes of kick-off.
The hosts would have added to their tally had it not been for a number of decent saves from Almeria goalkeeper Esteban, but the visitors offered little as an attacking threat and had their hopes of getting back into the game hit by the second-half dismissal of Marco Torsiglieri.
The result lifted Juan Ignacio Martinez's side, who had started the day second-bottom of the standings, out of the relegation zone and level on points with their opponents.
Valladolid went ahead from their first real attack, Manucho lashing past Esteban in the fifth minute.
The 38-year-old continued to be much the busier of the two goalkeepers as the half wore on.
First he was fortunate to get away with fumbling a Javi Guerra header, but he then twice got down well to tip two further Guerra efforts around the post.
Opposite number Jaime was called upon just before the half-hour mark, parrying a left-footed Suso drive from outside the area, but there were no further goals before the interval.
Esteban had to be alert at the beginning of the second half, diverting a Daniel Larsson blast away for a corner within four minutes of the restart.
Aleix Vidal could and perhaps should have got Almeria back on level terms soon after but contrived to send his close-range attempt wide.
Valladolid went within a whisker of doubling their advantage 20 minutes from time, but Jesus Rueda's fine free-kick struck the bar.
Almeria's quest to get back into the game suffered a setback 16 minutes from time when Torsiglieri was sent off for a second bookable offence for a foul on Manucho, having been yellow-carded in the first half for a challenge on Guerra, and the 10 men could find no way back.