Lille were staring relegation in the face just three matches ago and after two wins on the trot were one point off the relegation play-off spot prior to their match against Dijon last Saturday.
Man-of-the-moment Mothiba then stepped up to net twice for his side in their come-from-behind 2-1 victory, to secure their safety with one game to spare.
The 22-year-old Diambers Academy graduate, who returned to Lille after his 18-month loan to second division side Valenciennes was cut short in January, is delighted with his progress since his promotion to the senior team.
"I've been spending the most enjoyable period since I came back here [to Lille]. We're all very happy with our safety,” Mothiba said in a press conference ahead of their last match of the season against Saint-Etienne on Saturday night.
“My double [against Dijon]? I thank all my teammates for their trust. There's still one game left to play. We stay focused. We go there to give everything and win the match."
Having impressed in his first 13 Ligue 1 games, in which he has managed five goals and an assist, Mothiba has pledged his allegiance to the club and expressed his wish to remain on board next season.
"The LOSC is my club. This is my house. I want to stay here next season,” added the powerful frontman.
"For next season, I need to work in depth on my communication and my positioning. I also have some progress to make technically."