Goya had an eagle on the 16th hole at the Prosper Golf Resort and birdied the last two holes.
The 21-year-old Argentine had six birdies and a bogey on the second hole. He won his first European Tour title at the Madeira Islands Open BPI in Portugal in March.
John Bickerton and Steve Webster each shot 66 to tie for second.
Miguel Angel Jimenez, who designed the 7,155-yard course in Celadna, shot 71.