Roda JC enhanced their prospects of a Europa League play-off berth as Robbie Wielaert's goal 10 minutes before half-time sealed victory over FC Groningen at Euroborg.
The Kerkrade club inflicted a 10th defeat in 12 games on Groningen, whose own fading hopes of a top-eight finish took another major dent.
It was only Roda's third win on the road in the Eredivisie this season.
Groningen were the first to try their luck as Tim Keurntjes received possession in midfield and fired over from just inside the box.
Suk Hyun-jun headed over from close range in the 18th minute for the hosts following Lorenzo Burnet's cross from the left, before Roda forged their first opening seven minutes later as Moroccan forward Adil Ramzi cut in from the right and fired a shot wide of the target.
The only goal of the came arrived in the 35th minute as Jimmy Hempte's free-kick into the box caused confusion in the Groningen defence and Wielaert was on hand to turn the ball home from close range.
Danish forward Mads Junker wasted a wonderful opportunity to double Roda's lead from close range five minutes later after a defensive mix-up between Tim Sparv and Jonas Ivens.
Groningen tried to hit back early in the second period as Nicklas Pedersen headed over Henk Bos' free-kick, but other than Suk's header straight at Pawek Kieszek in the 57th minute, they were woefully short of ideas to get themselves back into the game.