Andre Silva grabbed his eighth league goal of the season to help Sevilla move top of La Liga with a narrow 1-0 win against Villarreal on Sunday.
After Barcelona drew at Atletico Madrid on Saturday, the door was open for the Andalusians to overtake them and victory at the Ramon Sanchez-Pizjuan puts Pablo Machin's side one point clear.
Silva headed Pablo Sarabia's inch-perfect cross home in the 30th minute to break the deadlock.
The hosts dominated the first half and could have increased their lead, but needed the offside flag to harshly rule out a Valladolid equalizer, when Enes Unal struck but Toni Villa was adjudged to be blocking Sevilla goalkeeper Tomas Vaclik's view.
Valladolid goalkeeper Jordi Masip produced a fine save to deny sparkling Sevilla playmaker Sarabia while Unal struck for the visitors but the goal was again disallowed for offside.
Vaclik made two fine stops late on to deny Daniele Verde and Unal but despite improving hugely in the second half Valladolid could not find a leveller and are 12th.
Earlier Jaime Mata earned 10th place Getafe a 1-1 draw at Athletic Bilbao, after Peru Nolaskoain opened the scoring for the hosts at the San Mames, who sit a disappointing 18th.
