Heerenveen maintained their challenge for the Eredivisie title courtesy of a battling 1-0 home win over NAC Breda.
Filip Djuricic netted the game's only goal 11 minutes before half-time at the Abe Lenstra Stadion to keep Heerenveen in third place and leave NAC fourth from bottom of the standings.
Djuricic had his first attempt in the 11th minute and, although he saw his shot blocked by keeper Jelle ten Rouwelaar, his second effort on target 23 minutes later proved more fruitful.
Rajiv Van La Parra fed Bas Dost, who in turn supplied Djuricic for a close-range finish which gave Ten Rouwelaar no chance.
Home keeper Brian Vandenbussche had to be alert two minutes into the second half to preserve his side's lead, fisting away a fierce 20-yard shot from Omar Bayram.
Djuricic and Luciano Narsingh almost combined to make it 2-0 six minutes later but the latter's effort was kept out by the sprawling Ten Rouwelaar.
Ten Rouwelaar was again at full stretch 20 minutes from time to keep out a Jeffrey Gouweleeuw piledriver which looked destined for the top-left corner, and soon after also tipped a Michel Breuer shot away for a corner.
The closest the visitors came to a late equaliser was Florian Jozefzoon's attempt five minutes from time, but to Heerenveen's relief it curled just wide of the post.