Negri headed into the game without the services of star striker Jean-Emmanuel Effa Owona, who was suspended after being sent off for violent behaviour in their previous match, while coach Azraai Khor Abdullah gave new centre-back Marian Farbak a chance to prove his worth.
On the other hand, the LIONSXII welcomed back vice-captain Hariss Harun from suspension, while young striker Khairul Nizam was named in starting XI in place of the injured Sufian Anuar.
And it was the Singapore outfit who took the lead in the 14th minute when a long throw from Madhu Mohana caused pandemonium in the Negri box, allowing centre-back Safuwan Baharudin the opportunity to stab home from close range.
Six minutes later, the visitors doubled their advantage when poor defending from Gengatharan Mahathevan allowed Khairul to waltz through and score after Irwan Shah had played a hopeful ball from the back.
Mahathevan made amends for his mistake just after the half-hour mark when he reacted quickest after Hyrulnizam Juma'at had fumbled a corner to pull one back for the hosts.
However, the Malaysia international's dirty day continue when he fluffed his clearance straight into the path of Shahril Ishak, allowing the LIONSXII captain to put his side 3-1 up.
The game was all but over 20 minutes from time when good play between Hariss Harun and Shahdan Sulaiman allowed to latter to bundle the ball home, although Negri added some respectability to the scoreline when Shukor Adan headed home a consolation four minutes from time.
Negri ended the game with ten men after goalkeeper Farizal Marlias hacked Hariss down with a brutal kick as the Singapore midfielder raced through on goal.
The result sees the LIONSXII move top of the table a point ahead of defending champions Kelantan, who now have two games in hand.