Home United made it eight games without a win against Albirex Niigata (S) in all competitions as they fell to a 3-0 defeat on Friday evening.
Atsushi Kawata ended his drought in front of goal with three well-taken headers, all coming in the second half at Jalan Besar Stadium.
The first half was devoid of chances, with Kawata arguably given the best opening in the seventh minute but he fired wide from a tight angle after pouncing onto a loose ball.
Both sides struggled to gain any rhythm thereafter and went into the break scoreless.
However, it took the White Swans only two minutes to break the deadlock after the restart.
Naofumi Tanaka was the architect of the opener as his cross from inside the box found an unmarked Kawata and the forward duly nodded home.
The Japanese side should have made it 2-0 just after the hour mark but Kento Nagasaki sliced his shot over after receiving Kawata's cross.
But Nagasaki made amends for that miss by providing the assist for Albirex's second goal, as his inswinging corner found Kawata at the far post and once again the latter was allowed to head past Zulfairuuz Rudy in the 71st minute.
Home's hope of a comeback was finally killed off two minutes from time, with Tanaka providing a cross once again for Kawata to score his hat-trick.
The Protectors could have earned a consolation goal in the dying minutes of the game but Irfan failed to put away Amir Zalani's cross at the post.
Home head coach Philippe Aw blasted his team for its poor defence and demanded improvement in the next few games.
"We didn't defend our corners properly, that was it," Aw told reporters at the press conference.
"In general, performance-wise we matched Albirex but it came down to individual errors ... the headers were free, all three goals were.
"We can do much better ... even though this season we have given a lot of opportunities to a lot of young players (due to injuries to the senior players) but they can do much better."