Barcelona failed to get the better of its opponent in terms of possession on Saturday, the first time in 317 competitive games that had occurred.
The Catalans cruised to a 4-0 victory at Rayo Vallecano (which included a hat trick from Pedro), but Gerardo Martino's side was edged out in the possession stats by 51 percent to 49 percent at Vallecas.
Long famed for its passing and possession philosophy, Barca saw more of the ball than its rivals in all of the 247 games coached by Pep Guardiola and in each of the 60 official matches bossed by Tito Vilanova. In total, the Blaugrana had the edge in possession for each of its last 316 competitive matches.
But just eight games into the 'Tata' tenure, Barca - with Alex Song in midfield instead of Sergio Busquets - saw slightly less of the ball than the home side on Saturday.
The last time that happened was on May 7, 2008 under Frank Rijkaard, when the Catalans lost 4-1 in a Clasico clash at the Santiago Bernabeu in La Liga.
Despite losing the possession battle, Barca stays top of La Liga with 15 points from five matches.