The Angolan had come close to breaking the deadlock in the first half with an overhead kick but made no mistake just after the hour when he was played in by Oscar Gonzalez and sent a fierce shot beyond Tono into the top corner.
Tono then did brilliantly to deny the former Manchester United striker a second moments later, but Granada could only force Dani Hernandez into one simple save from Floro Flores in their search for an equaliser as they remained just a point above the relegation zone.
Valladolid coach Miroslav Djukic had called for his side to be more lethal on home soil before the match and they controlled the game impressively without ever hitting top gear.
Indeed it was the visitors who had the better of the chances early on as Mikel Rico headed over from Dani Benitez's corner before Gabriel Torje flashed a shot just wide.
Valladolid grew into the game as the half wore on but Manucho just could not keep his acrobatic effort down as he swivelled to connect with Omar Ramos' cross.
The hosts started much the brighter in the second half, though, and after Patrick Ebert had pulled a shot just wide from the edge of the area they went in front as Oscar's fantastic pass split the Granada defence and Manucho showed great poise to fire across Tono and into the far corner of the net.
The goalkeeper then produced the save of the match to turn Manucho's downward header to safety from another Omar cross, but the introduction of Flores briefly gave the visitors the impetus.
The Italian should have done better when he shot into the side-netting 20 minutes from time and then could not make a powerful enough contact on Benitez's cross-cum-shot to trouble Dani, but Granada failed to muster another clear opening in the final 15 minutes as Valladolid held on to move back into the top half of the table.