Abstract: The invention relates to a sport-technical layer for use in an artificial lawn system in particular intended for sports fields, which artificial lawn system is built up at least of a substrate to which artificial grass fibres are attached as well as the sport-technical layer extending under said substrate, which sport-technical layer comprises at least one damping sublayer made of a synthetic foam, which damping sublayer made of a synthetic foam is built up of an essentially rigid flat plate, which plate is provided with flatness-enhancing means. The invention further relates to an artificial lawn system provided with such a sport-technical layer. According to the invention, the sport-technical layer is to that end characterised in that said flatness-enhancing means comprise at least one first slot assembly of at least two closely spaced slots formed in a respective upper surface or bottom surface of the plate, which slots extend in a first direction of the plate.