By Michael McCann
A 1-1 draw at the Mestalla meant Barcelona lost top spot in La Liga to Sevilla.
Barca are winless in four league games, their worst run since April 2016.
Valencia led in the second minute, Ezequiel Garay turning in from a yard out after a corner was not cleared.
Midway through the first-half Barcelona equalised, Lionel Messi combining with Luis Suarez for his 11th goal this season, and 22nd ever against Los Che.
Valencia deservedly secured a sixth draw from eight games, the most in the top five European leagues.