Sparta Rotterdam's worrying form hit a new low as they were thrashed by a Heerenveen side that played with 10 men for more than three quarters of their match tonight.
Heerenveen defender Michael Dingsdag was given his marching orders after just 17 minutes, but despite that the hosts led 3-0 at the break after Hernan Losada and Roy Beerens struck either side of a Gerald Sibon penalty.
Erik Falkenburg offered the slightest of consolations when he pulled a goal back on the hour, but even then Losada scored his second after 77 minutes to leave Sparta red-faced.
Frans Adelaar's side have now lost their past five matches and are a single point above the relegation play-off places having played a game more than ADO Den Haag and Willem II below them.
Losada fired the hosts ahead after nine minutes when he latched on to Viktor Elm's threaded pass from six yards.
Sparta should have got back on level terms when Dingsdag was shown his red card for a foul in the penalty area. Joshua John stepped up to take the spot-kick but it was saved by Henk Timmer.
Sparta were made to pay as they were effectively out of the match by half-time.
Sibon gave the hosts a two-goal cushion from the spot in the 38th minute after Ayodele Adeleye had pulled him down inside the area.
Beerens then made it 3-0 two minutes before the interval when he turned in Daryl Janmaat's cross from the right wing.
Sparta gave themselves a glimmer of hope on the hour when Falkenburg was on hand to force the ball home after Timmer had only been able to parry Darko Bodul's fierce long-range shot.
Sparta hardly deserved to get back into the game, however, and they conceded a fourth 13 minutes from the end when Losada accelerated into the area from the right flank and drove his shot low into the corner.