Nigerian striker Onyekachi Nwola gave the Red Warriors the lead after just two minutes although Felda immediately hit back through Azrul Ahmad.
Onyekachi put the hosts back in front in first-half injury time, before Kelantan wrapped things up with second-half strikes from Norfarhan Muhammad, Indra Putra Mahyuddin and Mohd Badhri Radzi.
The defending champions remain two points ahead of LIONSXII, who recorded a 2-1 win over T-Team at the Jalan Besar Stadium.
Shahril Ishak put the Singapore outfit in front in the 51st minute, only for Zairo Anuar to equalise two minutes later, before Shahdan Sulaiman sealed the win from the spot four minutes from time.
Elsewhere, Sarawak stunned PKNS FC with a 4-1 win courtesy of a Ashri Chuchu brace and further strikes from Shahrol Saperi and Vedran Muratovic, while Terengganu were held to a 0-0 draw at home to struggling Johor FC.
The day's final game saw Sabah and Selangor play out a 1-1 draw.
Saturday's Malaysia Super League Results
Kelantan 5-1 Felda United
Terengganu 0-0 Johor FC
PKNS FC 1-4 Sarawak
Sabah 1-1 Selangor
Friday's Malaysia Super League Results