Ex-Barcelona goalkeeper Jordi Masip saved a penalty from Lionel Messi but an earlier successful conversion sunk Valladolid at Camp Nou.
Lionel Messi netted his 30th goal of the season before missing his second penalty of the game as leaders Barcelona returned to winning ways in LaLiga with a 1-0 victory over Real Valladolid.
Gerard Pique won the 43rd-minute spot kick that proved the difference between the sides but, following back-to-back draws against Valencia and Athletic Bilbao in the top flight, Ernesto Valverde's men were again short of their fluent best.
Those previous results and Atletico Madrid's win over third-bottom Rayo Vallecano earlier on Saturday meant Barca went into the game with their now-restored lead at the top trimmed to four points.