Marcelino's side was already fourth going into the final league game of the season but both Getafe and Sevilla could have dislodged it had Valladolid earned an unlikely victory at Estadio Jose Zorrilla.
Carlos Soler settled Valencia's nerves with the opening goal after 36 minutes, and the result was made safe by Rodrigo Moreno's strike seven minutes after half-time.
Sevilla lobbied LaLiga to change the kick-off time ahead of its final league fixture against Athletic Bilbao, complaining that the temperatures in Andalusia would be too warm for their players, but the game went ahead as scheduled and Wissam Ben Yedder put it ahead after 44 minutes.
Athletic hit the crossbar late on as it pressed for an equaliser that might have landed it UEFA Europa League qualification but Sevilla countered and Munir El Haddadi scored in second-half stoppage-time to wrap up a 2-0 victory.
Meanwhile, Getafe was pegged back by a late Gerard Moreno goal as they drew 2-2 at home with Villarreal and it ended the season level on points with Sevilla, but its superior head-to-head record ensured it held on to fifth place.
Sevilla finished sixth and will have to play qualifying matches to earn the right to join Getafe in next season's UEFA Europa League, and Espanyol's 2-0 final day victory over Real Sociedad saw it climb two places to clinch the final UEFA Europa League qualification spot.
After starting the day in ninth place and going in goalless at half-time at RCDE Stadium, two goals in seven second-half minutes from Roberto Rosales and Wu Lei earned them three points and the opportunity to qualify for the UEFA Europa League, while Sociedad and Athletic missed out.