Feyenoord were the beneficiaries of goalline technology last week when they were awarded a winning goal when key rivals PSV goalkeeper Jeroen Zoet stupidly took the ball over his own line. This week, the lack of the technology has hurt them badly, as they were denied a vital goal against struggling Sparta Rotterdam.
Giovanni van Bronckhorst's men were 1-0 down within a minute thanks to a header from Mathias Pogba, but they tried to push on to get an equaliser to help protect their five-point lead at the top of the table.
Feyenoord ended the game with seven shots on target but registered no goals in a devastating loss.
The Rotterdammers have reason to be bitter, however, after Bilal Basacikoglu challenged the goalkeeper to a cross, only to see the ball bounce near the line and get caught up in the legs of Denzel Dumfries, who ended up walking it over the line. But the right-back reacted quickly and knocked it back into play for the goalkeeper to collect.
The ball looked to have crossed the line, but whether or not Basacikoglu fouled the shot stopper is up for debate.
As a result of Feyenoord's loss, Ajax can move to just two points behind them if they beat FC Groningen on Sunday.