It was the same winning margin by which he captured the World Golf Championships-HSBC Champions tournament in Shanghai in his previous start.
"I feel very satisfied," he said in a greenside interview in front of a large gallery.
The 24-year-old Japanese has finished first, second, first and first in his past four starts worldwide.
Matsuyama began his hot streak by winning the Japan Open by three strokes, before finishing second to American Justin Thomas at the U.S. PGA Tour's CIMB Classic in Malaysia.
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Matsuyama won the following week at the WGC event, before continuing his dominant run at the Taiheiyo Masters.
His status will be put to the test against a strong international field at the Dunlop Phoenix tournament in the southern Japanese city of Miyazaki, starting on Thursday.
(Reporting by Andrew Both in Tokyo; Editing by Mark Lamport-Stokes)
