Kelantan suffered their third successive league defeat after goals by Nazrin Nawi and Yashir Pinto in each half ensure a 2-0 victory for Perak.
Both set of fans clashed at the Sultan Muhammad IV Stadium and hurled objects at each other but the authorities acted quick to ease tensions and prevent a riot.
Kelantan are enduring a tough season
The 2012 treble winners were fortunate none of the teams below them, apart from bottom-placed Penang, collected points or else their season could have gone from bad to worse.
Kelantan are only five points away from the relegation zone with six matches left play.
Penang 3-1 win over Melaka United just about revives their aspirations but with games against Kedah and Pahang coming up next, escape could be a tall order.
Leaders JDT, meanwhile, had a rather comfortable match at Larkin as they extended their lead to 11 points over Kedah, who were held 1-1 by Selangor in Alor Setar.
The JDT express has no signs of stopping
JDT took the lead through MSL topscorer Mohammad Ghaddar in the 11th minute and could have sealed the match before half-time. Yet Sarawak's Sahil Suhaimi equalised in the second half, but Safawi Rasid came off the bench to assist a Ghaddar goal and get one for himself in a three-minute blitz.