Ormsby began the day tied for second place and just one shot off the lead but an early double bogey threatened to derail any chance of a good finish.
The 39-year old recovered well, however, and birdies at two of his last three holes saw him finish in a five-way share of 5th although six shots from the winner, Erik van Rooyen.
Ormsby moves to 77th in the Race to Dubai rankings and has opened the door at least to qualify for the season-ending DP World Tour Championship in Dubai in which the leading 50 players in the Race to Dubai rankings play for the riches of that event and the bonuses available from the season-long race.
South African, Van Rooyen, won his first European Tour title after a run of outstanding form and near misses in 2019 but was forced to hold off a strong challenge from England's Matthew Fitzpatrick who had won the equivalent of this event in 2016.
Jason Scrivener finished as the next best Australian when he tied for 20th, Deyen Lawson saved his best for last when he recorded a final round of 66 to finish 53rd and Brett Rumford was 73rd.
Scrivener is now 56th in the Race to Dubai rankings in which the leading Australian is Scott Hend in 39th place. Hend missed the cut this week.
The European Tour now moves to Crans-Sur-Sierre in Switzerland for the Omega European Masters.
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