In a perfect first half display by Thorsten Fink’s men, it took Olarenwaju a space of five minutes to score both goals which came in the 16th and 21st minutes.
Tarkan Serbest wrapped up the victory with a strike of his just after the half-hour mark.
The goals marked the 24-year-old striker’s 16th of the season in 31 Austrian league encounters. Which has seen him moved level with Sturm Graz's Deni Alar at the top of the goalscorer's chart.
And he has bagged 23 efforts in all competitions for the Violets, placed second in the log, eight points adrift of table-toppers Salzburg after 33 games.
Austria Wien will face Wolfsberger AC in their next league tie on May 20.