Bueno drove towards goal and had the first effort after nine minutes, but his strike was wide of the mark.
Valladolid continued to put pressure on the home side and came close when Omar put a shot just wide.
Raul Rodriguez had Espanyol's first meaningful effort on goal on 23 minutes, although he could not direct his header on target.
Manucho came close to giving the away side the lead just before half time, but his header was off-target.
Manucho had the first effort of the second half after 47 minutes, but failed to direct it towards the goal.
Espanyol had a chance to take the lead on 66 minutes through Simao, but the winger's shot missed the target.
The home side continued their resurgence and came close again on 70 minutes through Joan Capdevila, but his header never troubled the goalkeeper.
Gomez broke free for Espanyol on 77 minutes, but his finish was wide of the mark.