The Australian, who is currently ranked seventh in the world, appeared to be struggling when 'The Rocket' moved into a 3-2 lead after making a break of 143.
However, the 2010 world champion maintained his composure and rattled off four frames in a row to record his first victory since his triumph in the Riga Masters 13 months ago.
The 35-year-old, who also beat world number one Mark Selby and home favourite Marco Fu en route to the final, was quick to pay tribute to the supporters at the Queen Elizabeth Stadium in Hong Kong for creating a superb atmosphere throughout the tournament.
"I played in world finals, UK finals, Master finals, but nothing compares to the atmosphere tonight," said Robertson.
"The crowd has been wonderful all week. I had to play against two crowd favourites in Marco Fu and Ronnie O’Sullivan but this crowd is warm to when the other guy plays good snooker, too. It’s nice to play so well in such a wonderful tournament and especially with this kind of set-up tonight."