The Nigeria international doubled his side's tally in the 29th minute after an Andreas Ulmer's own goal had gifted them the lead. But Amadou Haidara pulled one back for the visitors before the break.
After the restart, Thorsten Fink's men were outclassed as Oscar Garcia's side rallied back through Hee Chan Hwang and Valentino Lazaro scored in the 64th and 66th minutes respectively to seal the maximum points. The 24-year-old was cautioned in the 83rd minute.
Olarenwaju now leads the Austrian topflight goalscorers chart with 17 goals from 33 appearances.
Despite the loss, Austria Wien remain second in the log with 60 points from 35 games and they face fifth-placed Admira in their final league outing at the BSFZ Arena on May 28.