Mitrovic, Mbemba and Praet all scored. Harbaoui made the only Lokeren goal thanks to a penalty.
Anderlecht would have been certain of the championship with only one point from this match, but in the event picked up three points.
Standard de Liège beat Racing Genk at home 1 - 0 thanks to a goal from Carcela, but Anderlecht's win in Brussels means that Standard fall two points short in the race to secure the championship.
Club Brugge trounced Zulte Waregem 2 - 0 at home thanks to goals from Gudjohnsen and Castillo. As a result Anderlecht top the Play-off I table followed by Standard. Club Brugge are third, ahead of Zulte Waregem. Lokeren are sixth ahead of Racing Genk.
OH Leuven are relegated after a 1-0 defeat against Mouscron.