The Warriors defeated Home United 2-0 at the Choa Chu Kang Stadium.
Former Lions skipper Indra Sahdan played a big part in that victory against his former employer, the Protectors, as he started it when he won a spotkick just 10 minutes after he came off the bench.
Ivan Jerkovic step forward and dispatch the penalty.
Then afterward, Indra scored the decisive second goal to kill off the Protectors.
This was the Protectors first defeat in 26 matches - the longest undefeated run in S-league history.
With that victory, the Warriors took over the top of the table for 24 hours until the matchup between Etoile FC and Tampines Rovers at Jalan Besar.
Whoever won will go to the top of the table and it was Tampines Rovers that prevail as they defeated Etoile FC 2-1.
The Champions had started off brightly with Kevin Lefranc scoring after Hassan Sunny make a shocking error and drop the ball into his path.
After that, the French side had several chances to extend that lead but they spurned it and the Stags were lucky to go into the break only one goal down.
In the second period, the Stags came out strongly and dominated the game but they could not make any chances until Aleksandar Duric step up, as he always does, for the 40-year-old could not miss after Akihiro Nakamura miscued his shot to give him an open goal just a few step away from goal.
Duric returned that as he set up the Stags winner by muscling off his defender to hold up the ball and lured other defenders to him and then laying it off to an advancing Akihiro Nakamura to fire into the net.
It was a remarkable comeback for the Stags who now lead the table with 20 points.
In another match, the White Swans strengthen their claim on the best of the rest or aka fifth spot by defeating Balestier Khalsa 1-0 with Musashi Okuyama scoring the only goal.
Shahril Jantan (GK) (C), Shaiful Esah, Hafiz Osman (Razaleigh Khalik), Bah Mamadou, Daniel Bennett, Noh Rahman, Ivan Jerkovic, Rhysh Roshan Rai, Taisuke Akiyoshi, Mustaqim Manzur (Daniel Hammond), Fazrul Nawaz (Indra Sahdan)
Lionel Lewis (GK), Kenji Arai, Juma'at Jantan, Valery Hiek, Shi Jiayi (C), Nor Azli Yusoff, Isa Halim (Kim Dae Eui), Asraf Rashid (Farizal Basri), Firdaus Kasman, Frederic Mendy, Sufian Anuar (Firdaus Idros)----------
Hassan Sunny (GK), Seiji Kaneko, Benoit Croissant, Ahmad Latiff (Zahid Ahmad), Akihiro Nakamura, Shahdan Sulaiman, Imran Sahib, Ismadi Mukhtar (Jamil Ali), Aliff Shafaein (Shukor Zailan), Park Yo Seb, Aleksandar Duric (C)
Joey Sim (GK), Anaz Hadee, Lim Young Woo, Paul Cunningham (C), Ishak Zainol, Ridhwan Osman, Armanizam Dolah, K Vikraman, Poh Yi Feng (K Sathiaraj), Vitor Borges, Kim Young Kwang (Andrew Tan)