Riley, who performed wearing a custom made House of Emmanuele crystal mask and a dramatic white dress with a long train, sang Not the Same.
The ballad is inspired by Riley's experience with Asperger's Syndrome and feeling different to everyone in his appearance and how he related to the world.
Riley has made it through to the grand final of the Eurovision Song Contest, along with singers from nine countries out of the other 17 that were also competing for a spot.
Half of the votes were cast by a professional jury and the other half remotely by viewers.
Performers from Belgium, Czech Republic, Azerbaijan, Poland, Finland, Estonia, Australia, Sweden, Romania and Serbia garnered enough votes to make the cut for the final.
The 10 successful nations will join Lithuania, Switzerland, Ukraine, Netherlands, Moldova, Portugal, Iceland, Greece and Norway which qualified from the first semi-final — in Sunday's decider.
Hosts Italy, Germany, France, Spain and the United Kingdom — the big five countries that make the most significant financial contributions to the European Broadcasting Union, which broadcasts the song contest — have all bypassed the semis per the rules.
Greece’s Amanda Georgiadi Tenjford takes to the stage with her ballad “Die Together” her performance is “Theatrical”, with Amanda, wearing a long sheer white gown, all alone on stage. Her staging features a blue LED backdrop, with empty fallen-over chairs strewn across the floor; during the chorus, the lighting rig is used to full effect to build drama in her performance.