Chelsea midfielder Bertrand Traore struck for Vitesse Arnhem in their 1-1 draw with Ajax in Holland.
Ajax could have been crowned champions on Sunday if results went their way, but instead they must stave off fast-finishing Feyenoord over the final three games.
Feyenoord moved six points adrift of the leaders with a 2-0 win over RKC Waalwijk.
Ajax had to come from behind to take a point at Vitesse as Kolbeinn Sigthorsson (47) cancelled out the opener from Chelsea loanee Traore (27).