The US Open champion, who upset Serena Williams in the final in NY this month, overpowered her unseeded opponent with a dominant serve and will face fourth-seeded Karolina Pliskova in Sunday's final. "I knew I had to play aggressive and make her move around the court, to play with all the energy I had in me and to be positive all the time - that was the goal".
"Naomi was playing so good the whole tournament, the future is bright".
Osaka had drawn a first-round bye in Wuhan and was scheduled to play either China's Zhang Shuai or Australian wild card, Samantha Stosur, in the round of 32 had she not pulled out.
Osaka's defeat was her second in the tournament final, having also been runner-up in 2016, as the 20-year-old seemed to finally succumb to the after-effects of her emotional U.S. Open triumph earlier this month.
Pliskova then served out the match with a love game, sealing the victory with an ace.
"It was another long one today!"
The former world number one started as if intent on finishing the contest as quickly as possible, storming to a 4-0 lead before wrapping up the first set in less than half an hour.
Osaka advanced to face world number eight Pliskova in the final after the big-serving Czech outlasted Croatia's Donna Vekic 6-2 4-6 6-3 in a topsy-turvy match that lasted more than two hours.
Pliskova is set to climb to the seventh position in the WTA rankings and strengthens her chances of competing in a third consecutive WTA Finals Singapore.
Her rally ended up falling just short as Wozniacki served out the match, drawing an error from Osaka on match point to take her first title of the year.
"I was just happy it didn't go to a third set", Pliskova said.
The final in Tokyo will be the second WTA final for her this year.
But never the less, the fourth seed Karolina Pliskova, slowly turned the screw and broke for 3-2 with a fizzing backhand. Pliskova said after her victory.
In contrast, a tearful Osaka could barely bring herself to speak at the trophy presentation.
But Osaka was still proud she had made the Tokyo final and added: "To play the final of the US Open and then to come here, I think I did pretty well".
"I've literally never felt more exhausted in my entire life, so I kind of want to say the chances of me playing in the next tournament are very low", she said.