Michael de Leeuw's first-half penalty was enough for Groningen as they beat Willem II 1-0 in the Eredivisie this afternoon.
The hosts were awarded the spot kick shortly after the half-hour mark when Jerson Cabral handled inside the box.
De Leeuw made no mistake from 12 yards before the home side went close in the second period through Danny Hoesen, Tjarron Chery and Maikel Kieftenbeld.
Willem spurned the chance of a late equaliser when Stijn Wuytens fired wide when well placed inside the box.