 Rantie proceeded to score a hat-trick in his competitive debut for the club on 20 August 2012 when Malmö FF played Sandvikens IF away from home in the second round of Svenska Cupen, Malmö won the match 6–3 after extra time.On 27 August 2012 Rantie made his first league appearance for Malmö FF when he came into the game from the bench in the 62nd minute against GIF Sundsvall.Rantie later scored his first league goal for the club in the 89th minute, affirming the end result 2–0 for his new club.