Hakim Ziyech scored a goal while Andre Onana conceded six goals in Ajax's 6-2 defeat to Feyenoord in Sunday's Klassieker.
The African duo were in action for the entire duration of the eight-goal thriller as Erik ten Hag's men suffered their heaviest defeat of the season.
With Ajax trailing by 2-1, Ziyech drew them levelled in the 33rd minute with his 11th league strike of the season which makes him the second highest goalscorer for Amsterdam outfit in the Dutch top-flight after Dusan Tadic with 12 goals.
His effort was not enough for the visitors at the Feyenoord Stadium as Robin van Persie's brace and goals from Trindade Vilhena, Jens Toornstra, Steven Berghuis, Yassine Ayoub left them five points behind league leaders PSV.
Ajax remain unmoved in the second spot with 47 points from 19 matches and they will be looking to bounce back to winning ways when they host VVV-Venlo for their next Eredivisie match on February 2.