Juan Ignacio Martinez's side had slumped to 17th as a result of their poor run of form, but a sensational Patrick Ebert effort and Javi Guerra's calm finish put them into a 2-0 half-time lead at the Campo de Futbol de Vallecas.
And Daniel Larsson completed the scoring shortly after half-time as Valladolid leapfrogged Vallecano in the league standings.
It took 31 minutes for the deadlock to be broken, but the game was sparked into life by Ebert's terrific strike.
The 26-year-old picked up the ball on the right and cut in before unleashing an unstoppable left-footed effort into the far corner.
And Valladolid doubled their advantage six minutes before the break.
Guerra was set free by Fausto Rossi on the right, and he kept his composure to coolly slot beyond Ruben from the right-hand side of the penalty area.
Martinez's charges continued to dominate proceedings after the restart, and went 3-0 ahead in the 48th minute.
Larsson - who replaced Ebert at half-time - made a darting solo run before rounding the onrushing Ruben and slotting into the empty goal.
The Swede almost notched a second in the closing stages, but his left-footed effort was well saved by the goalkeeper.
It made no difference however, as Valladolid secured their second win of the season, while Vallecano's recent resurgence - which saw them record back-to-back league victories - was brought to an abrupt end.