The UAE ace held his nerve in a tense final to clinch the title, shooting a final score of 102.8 for an overall total of 694.8 to edge out Spain's Juan Antonio Saavedra Reinaldo by just 0.2.
There was medal joy for the Host Nation too as Great Britain's Matt Skelhon took bronze with a total of 693.2
Sweden's veteran Jonas Jakobsson - the most decorated male Paralympian of all time - missed out on adding to his amazing medal haul as he finished in fourth.
Afterwards, Alaryani said: 'It's amazing. I was sure that I was going to get the gold.
'It's a dream - the first time I've won gold and the first gold medal for UAE in this competition (London 2012). It's everything for me.
'From the day I finished the last Paralympic Games I started immediately planning for this one. I was very focused on London.'