AMSTERDAM, Aug 18 (Reuters) - New Brazilian signing Ari struck twice to inspire AZ Alkmaar to a 4-0 win over VVV Venlo in the opening weekend of the Dutch league on Saturday. Ari set up Kemy Agustien after six minutes to open the scoring and doubled the lead himself 25 minutes later. Just within the hour Ari converted a penalty to make it 3-0 and with 10 minutes remaining Haris Medunjanin completed the rout. Alkmaar are top with three points ahead of Groningen, who made a convincing start with a 3-0 away win against 10-man NAC Breda. Goran Lovre opened the scoring on the stroke of half-time and, after NAC had Patrick Mtiliga sent off early in the second half, Erik Nevland and Mark Jan Fledderus sealed the victory for Groningen. Twente Enschede, fourth last season, recorded a 2-0 win at Excelsior Rotterdam with Blaise N'Kufo scoring both goals. Belgian Ronald Lamah struck in the 85th minute to salvage a point for Roda JC Kerkrade in a 1-1 draw at NEC Nijmegen, who opened the scoring six minutes before the interval with Jhonny van Beukering on target. On Friday, Heerenveen and Willem II Tilburg shared the points in a goalless draw. PSV Eindhoven, Ajax Amsterdam and Feyenoord will be in action on Sunday at Heracles Almelo, Graafschap Doetinchem and Utrecht respectively.