Play-offs, final stage

First leg matches

Four teams qualified for the final stage, where they will play-off over two legs for the two remaining promotion spots. As chance would have it, two teams from each of the regional groups III & IV made it through, but with rankings in the regular season taking preference over the rule keeping sides from the same group apart, Extremadura will play Cartagena, and Elche will meet Villarreal B. (10.06.18)

Second leg results were as follows (teams promoted in bold):

Finals, second leg
23 Jun Villarreal B
Rubén Mesa (2)
2-1 Elche
Benja
24 Jun Cartagena
0-0 Extremadura