A late error by Valladolid goalkeeper Jaime Jimenez gave Real Betis a 1-0 away victory in the Spanish league on Monday.
Jimenez let an easy ball slip from his grasp in the 89th minute, allowing Betis striker Ruben Castro to take advantage for the late winner.
It was Betis' first match in three weeks because of the international break plus its game against Atletico Madrid being rescheduled because of the European Super Cup.
Valladolid endured a second straight loss after starting the season with two victories.
Betis is six points behind leader Barcelona, which has 12. Malaga is next with 10, followed by Sevilla and Mallorca with eight. Real Madrid is eight points adrift of Barcelona after a terrible start.