In what was a pulsating final, Walden and Allen went toe-to-toe, with neither player able to pull more than two frames away from his opponent until the final three frames of the contest.
Walden had a rather comfortable passage through to the final – not having to face a top-16 opponent en route – but his quality shone through against Allen as he collected his third world ranking event from three finals.
Allen, who has arguably been the most consistent player on tour this season, surrendered the first frame but soon hit back to level.
World number 11 Walden then took a 3-1 lead but Allen kept his cool and collected four of the next five frames, with breaks of 113 and 52, to lead 5-4.
The contest continued to ebb and flow, and as the evening session got under way Walden won the first three frames – a break of 85 the highlight.
Allen soon fought back to level at 7-7, but Walden turned on the style to seal the win with the final three frames.
"I couldn't be happier," Walden told World Snooker. "It was a tough first session today, and then I got better in the second session. It's a dream come true to win this event. All three of my titles have come in China and I love playing here.
“It was a tiring tournament with long matches, but I've being trying to get enough rest in between, to keep myself going.
"I've not thought about the money. It was just so important for me to get my hands on the trophy. The money is just a bonus. My wife will find a good place for it."