Nigerian international Kayode, who is on loan at Shakhtar from newly crowned English Premier League champions Manchester City, scored his side’s fourth goal of the encounter in the 74th minute
Brazilian forward Taison Barcelos put Shakhtar ahead on eight minutes, while Igor Tyschenko equalised for Mariupol in the 22nd minute.
Shakhtar regained the lead through Marlos Romero 16 minutes later with Taison, Kayode and Ivan Petryak adding three more goals in the 47th , 74th and 81st minutes respectively.
Kayode has now featured in three games in all competitions for his club and has hit the back of the net twice.
Shakhtar will face Dynamo Kiev, who beat Dnipro 4-1 in the other semi-final, in the final on May 9 at the Dnipro Arena.