Denzel Dumfries scored the winning goal against his former club as Heerenveen overcame Sparta Rotterdam 2-1 at the Abe Lenstra Stadion.The 21-year-old defender, who came through the ranks at Sparta, struck as the midway point of the second half approached to ensure his team recorded back-to-back home victories for the first time this season.The hosts had to come from behind to do it though after Julian Chabot put the Eredivisie's bottom club ahead after only three minutes.Former Charlton forward Reza Ghoochannejhad equalised after a quarter of an hour with his first goal since September before Dumfries scored in the 65th minute.