AZ Alkmaar (the leading club from the Dutch city of Alkmaar) secured a 3-2 comeback victory away at SC Heerenveen to extend their flawless start to the Eredivisie season to five wins from five games. The visitors trailed 2-1 at half-time after defensive errors allowed Heerenveen to overturn an early AZ lead, prompting coach Leeroy Echteld to make two substitutions at the break. Second-half substitute Valdemar Byskov, a 21-year-old Danish debutant signed from FC Midtjylland, set up the equaliser for Meerdink in the 69th minute, before fellow substitute Ayoub Oufkir chipped the winning goal to keep AZ the only side without a dropped point in the Dutch top flight.