Kelantan could join them in the second division next year after JDT secured a comfortable victory at Larkin Stadium, thanks to goals from S. Kunanlan, Gonzalo Cabrera and Safiq Rahim.
With the league title wrapped in August, JDT were looking forward to a massive title celebration in front of their home fans. But that did not mean they took this game lightly, as they put the visitors to the sword from the start.
That early dominance turned into the seventh-minute penalty after Kelantan left-back Qayyum Marjoni handled in the box.
But JDT striker Mohammed Ghaddar failed to add to his 23 league goals in 2017 after Kelantan goalkeeper Khairul Fahmi Che Mat pulled off a stupendous one-handed save to deny him from the spot.
The national custodian, however, turned villain just 10 minutes later after he completely misjudged S. Kunanlan's cross-cum-shot, which flew over him into the net.
The Southern Tigers' threats mostly came through the right flank, with Natxo Insa heading just over before Gabriel Guerra fired inches wide in quick succession.
In the 37th minute, JDT added to their tally after capitalising on another Kelantan error.
Kelantan's S. Subramaniam lost possession after attempting to push forward from defence, and Ghaddar was quick to feed Guerra on the right.
The Argentine turned provided for Cabrera with sumptuous low cross, on which his Argentine teammate capitalised to make it 2-0.
The hosts did not let up after the break, coming out with clear intentions to add to their advantage and compound Kelantan's miserable night.
Shortly after, Guerra saw a goal chalked off for offside, JDT went 3-0 up on 55 minutes, thanks to Safiq.
The captain's curling free kick on the edge of the box eluded everyone, including Khairul Fahmi, to nestle in the bottom corner.
That effort was Safiq's ninth league goal of the season, making him the highest-scoring Malaysian player, with two games remaining.
JDT continued to dominate a poor Kelantan side who just could not get any possession, let alone get out of their half to create openings.
Natxo Insa expertly side stepped Daudsu Jamaluddin to force a fully-stretched save from Khairul Fahmi, before blazing just wide in the final 10 minutes.
It was the perfect warm-up gift for JDT's title celebrations, including an open-top bus parade. For Kelantan, it was a stark reminder that life in the lower division could await if they fail to get results in their last two games.
The Red Warriors still have their heads just above water, as 11th placed Sarawak also lost 3-0 to Pahang, with Christie Jayaseelan bagging a brace.
Pahang replaced Kedah in second place after the Red Eagles lost to Felda United 3-1.
Other results saw Melaka United beat Perak 3-1, while PKNS FC also humbled Selangor 2-1.
Johor Darul Ta'zim: Izham Tarmizi (GK), Natxo Insa, Gary Steven Robbat, Junior Eldstal, Safiq Rahim (C), S.Kunanlan,Fadhli Shas (Aidil Zafuan 70'), Fazly Mazlan, Mohammed Ghaddar, Gonzalo Cabera, Gabriel Guerra (Safawi Rasid 64')
Kelantan: Khairul Fahmi Che Mat (GK), S.Subramaniam,Qayyum Marjoni, Abou Bakr El Mel, Mamadou Danso, S. Thinagaran, Daudsu Jamaluddin, Khairul Izuan Rosli,Margaro Gomis, Indra Putra Mayhuddin (C), Alessandro Celin
