Cabrera-Bello was tied at 11-under-par with Ormsby, who also closed with bogey, heading to the last but sent his second shot into the bunker to finish second at 10-under alongside Julian Suri (66), Paul Peterson (67) and Alexander Bjork (68).
"It means a lot to me," said 37-year-old Ormsby, who was playing in his 264th European Tour event.
"I've played a lot of golf in Europe, everywhere and a few bumps along the way but it's pretty cool to get a win this late in your career.
"I probably won't sleep too much on that flight on the way to Oz tonight."
Race to Dubai champion Tommy Fleetwood fired a final round 69 to finish sixth in the season-opening European Tour event, which is co-sanctioned by the Asian Tour.
Indian SSP Charawsia, who held a one-shot lead coming into the final day, dropped of top spot after a triple-bogey just before the turn and eventually finished in a share of seventh after a 72.
Spaniard Cabrera-Bello (70) finished runner-up for the second year in a row while last year's champion Sam Brazel finished in share of 23rd.
(Reporting by Aditi Prakash in Bengaluru, editing by Nick Mulvenney)
