The Young Tigers, fresh off the back of their 2011 SEA Games triumph, got their tour off to a flying start with a 3-0 win over Sydney FC last Tuesday, before falling to a 1-0 defeat to the Mariners.
However, Ong's charges got back to winning ways on Monday, taking a 4-0 lead through Thamil Arasu, Ahmad Fakri and a brace from Ahmad Hazwan, before Ben Jurman netted a late consolation for Central Coast.
And the Malaysian coach believes there are plenty of positives to be taken from their victory over the A-League leaders.
"My players combined well and were disciplined throughout the match," Ong told the New Straits Times. "They played to their strength in every department.
"I hope this victory over a team who lead the A-League standings will help improve [our] confidence.
"[It was] a great way to end our season, but my players need to work harder as they still lack in some areas."
Fakri has recently been criticised for some lacklustre performances, but was back to his best on Monday, earning praise from Central Coast coach Graham Arnold.
Nonetheless, his coach believes there is still improvement to come from the 22-year-old Felda United forward.
"Ahmad Fakri played one of his best matches of the season today [Monday]," Ong added. "He almost single-handedly earned our team this victory.
"Arnold congratulated him after the final whistle. He, however, needs to be consistent if he hopes to go far.
"Ahmad Fakri is starting to get his form back after a slow start to the season. I hope to see him get better."
The Young Tigers are currently regarded as the best U-23 side in Southeast Asia, following consecutive victories at the 2009 and 2011 SEA Games