Heerenveen secured a surprise 2-0 home win over 10-man PSV Eindhoven on Sunday.
Feyenoord moved top of the Eredivisie with a 5-0 thumping over Willem II on Sunday afternoon.
PEC Zwolle came from behind to open their Eredivisie account with a 4-2 victory over Roda JC, while champions Feyenoord beat FC Twente.
PSV conceded a last-minute equaliser at FC Twente as their hopes of catching the Eredivisie's top two suffered a setback.
Three points separate Feyenoord and Ajax at the top of the Eredivisie after the latter toppled the former 2-1 on Sunday.
PSV Eindhoven bounced back from the defeat by Eredivisie leaders Feyenoord to sweep past Roda JC 4-0 at Philips Stadion.
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