Former Enyimba forward Ibrahim Mustapha netted the decisive goal in the third minute.
Plateau United now top the table with 32 points from 18 games.
Kano Pillars continued their impressive run courtesy of a 2-0 home win against Adamawa United at the Sani Abacha Stadium.
Auwalu Ali and Achibi Ewenike scored both goals for the Sai Maisugida.
Pillars moved from 12th to 8th position in the table following the win.
In Nnewi, FC Ifeanyiubah and Akwa United battled to a 0-0 draw in a thrilling encounter.
Wikki Tourists and Dakkada FC also share the spoils at the Abubakar Tafawa Balewa, Bauchi with the game ending in a 1-1 draw.
The hosts took the lead through Daniel Jackson in the 68th minute, while Femi Ajayi equalised for Dakkada three minutes from time.
Nasarawa United boosted their survival hopes with a 3-1 win Abia Warriors in Lafia.
Emmanuel Ugwuka gave Abia Warriors the lead in the third minute, but the home team rallied back through goals from Abdallah Mohammed, Chidi Solomon and Haggai Katoh.
Kwara United also beat MFM 1-0 in another matchday-18 encounter at the Kwara Sports Complex, Ilorin.
Christopher Nwaeze scored the winning goal for the hosts from the spot in the 73rd minute.
At the Okigwe Township Stadium, Heartland defeated Sunshine Stars 1-0 with Abiodun Thompson scoring the winner in the third minute.
MATCHDAY 18 RESULTS
Jigawa GS 1-0 Lobi
FC Ifeanyiubah 0-0 Akwa Utd
Heartland 1-0 Sunshine Stars
Kano Pillars 2-0 Adamawa Utd
Kwara Utd 1-0 MFM
Plateau Utd 1-0 Rivers Utd
Wikki 1-1 Dakkada
Nasarawa Utd 3-1 Abia Warriors