Awoniyi came off the bench in the 56th minute and required only five minutes to open his Bundesliga account and begin a comeback for his side.
The 22-year-old found space in the penalty box to tuck in a low cross from the right as Mainz battled to secure a 2-2 result that earned a valuable point near the foot of the table.
Earlier in the day, Reds defender Nat Phillips - pictured above - played just short of an hour as VfB Stuttgart resumed their 2. Bundesliga campaign with a 2-1 defeat at Wehen Wiesbaden.
The German divisions restarted this weekend following the suspension of football due to the COVID-19 pandemic, with Marko Grujic involved in a win for Hertha BSC on Saturday.