The double world champion team, featuring BJ Neufeld, Colton Flasch and Denni Neufeld, stole in the third and sixth end to keep the host nation on the back foot.
Koe, whose draw to the button with the final stone secured victory, revelled in becoming the first-ever winners of the new event, yielding prize money of $USD 39,000.
"We're super happy and it was a lot of fun out there," said the skip.
"We've had a great year and it's awesome to win here. All week, we've been really impressed with the event and it feels good to win the Grand Final.
"The Chinese team played really great and we wish them the best going forward."
Canada were also victorious in the women's competition, with Jennifer Jones leading them to a dramatic 9-6 victory over Switzerland.
But a full set of three victories eluded them as Norway's Kristin Skaslien and Magnus Nedregotten combined to beat Laura Walker and Kirk Muyres 8-3 in the mixed doubles final.
Round 1, Qualifying & Race 1 - Donington Park