The 24-year-old forward scored her second goal of the season on her 12th appearance as Hope Powell's side sealed their first away win in the English topflight this term.
The visitors started well as Laura Rafferty gave them the lead in the 34th minute after Umotong's fierce effort was deflected to the path by the crossbar in the first half.
The Nigerian's relentless effort to get on the score sheet finally paid off when she fired past Liverpool keeper Anke Preuss four minutes after the restart to cement Brighton's win at the Prenton Park.
48: Goal. A second for Brighton from Umotong.— Liverpool FC Women (@LiverpoolFCW) January 6, 2019
Umotong has been recalled to the Super Falcons' fold for this month's Chinese Invitational tournament after almost three years out ahead of the summer’s Women’s World Cup.
The win moves Brighton out of the relegation zone to ninth spot in the 11-team WSL log with nine points from 12 games and they will take on Manchester City in the Continental Tyres League Cup quarter final on Thursday.