The Nigerian superstar delivered a perfect assist for Mario Lemina, who scored the decisive goal, leaving the Premier League side with a daunting task for the return leg.
After the match, Osimhen boldly declared that Galatasaray have the quality to complete the job at Anfield.
During a post-match interview on TRT, accompanied by his child, the former Napoli man reflected on his personal connection to the club and explained why this triumph felt deeply significant.
"I have been very happy since I arrived in this jersey. This jersey is very special. I wanted to do my best for these fans. I lost my mother at a very young age. That's why it's very important to me.
"We are a family together with the Galatasaray fans. We did a very good job today.
"I think we can hurt Liverpool in the second leg. We have done a good job so far.”