 He played as a defensive midfielder until 2004, when he was moved to centre back by coach Américo Gallego and he captained the team that won the 2004 Apertura tournament, thus breaking the club's 12-year title drought.The central defender played 18 games (out of 19) during the tournament, all of them as a starter.After winning the league championship with Newell's, Domínguez was purchased by third-party Media Sports Investment for $2.5 million (US), that loaned him along with fellow Argentine players Carlos Tevez and Javier Mascherano to Brazilian side SC Corinthians.