"My serve is my biggest weapon and it was key today", she added. "I really wanted to get to the final".
Prior to the final, Pliskova had spent 419 minutes on court, more than any other player and nearly twice as long as Osaka, but the Japanese player soon wilted and was unable to match the brilliance that secured her a first Grand Slam title.
Naomi Osaka, right, of Japan and Karolina Pliskova, left, of Czech Republic shake hands after Pliskova won their final match of the Pan Pacific Open women's tennis tournament in Tokyo Sunday, Sept. 23, 2018. "Naomi was maybe a little bit exhausted, you could see that, but the future is bright for her and congrats to her for an incredible few weeks".
The title is the 11th of Pliskova's career and her fifth straight triumph in a final.
Croatian Vekic shocked world number four and second seed Caroline Garcia 6-3 6-4 to continue her unlikely run at this event.
The players had split their previous two meetings, but Osaka started the final as favourite after her historic NY triumph.
Both players are in the top 10 in terms of number of aces served on the tour this year. She served well against Vekic, making 78% of her first serves, winning 71% of those points, and will need to find similar numbers against Osaka who she can not match off the ground.
Currently just outside the eight qualifying spots for next month's WTA Finals in Singapore, Pliskova has now spent 420 minutes on court in Tokyo compared to 222 minutes for Osaka. But Pliskova slowly turned the screws and broke for 3-2 with a fizzing backhand which her opponent swished well wide.
Iran's Revolutionary Guard vows 'revenge' over parade attack
Iran will be scrambling to determine the motives for the Saturday's high-profile attack as it faces growing US pressure. Shooting broke out several minutes into the event, which featured troops from the Iranian Army's 92nd armored division.
New Galaxy A7 comes with more cameras
The teasers reveal that the smartphone will be equipped with Dolby Atoms for surround sound experience and triple rear cameras . The bottom camera has an 8MP (F2.4) Ultra Wide lens offering up to 120 degrees, capturing unrestricted wide-angle photos.
ABC boss Michelle Guthrie ousted from role as managing director
The chairman praised Ms Guthrie's performance in relation to the ABC's adaptation to the digital environment. Sally Neighbour, executive producer of 4 Corners, tweeted: "excellent decision".
"I know that she's a great player", Osaka said of Pliskova.
Before the final, Pliskova, 26, had spent 419 minutes on court, more than any other player and nearly twice as long as Osaka, but the Japanese world No. 7 soon wilted.
For Pliskova, it was a first tournament victory since Stuttgart in April - and the first since wedding long-time partner Michal Hrdlicka in the summer.
"The first one this year was before the wedding", she said.
In contrast, a tearful Osaka could barely bring herself to speak at the trophy presentation.
Osaka, 20, admitted she was exhausted, saying: "I haven't really had much time to rest, so I feel exhausted right now".
"I think Donna was playing well and she's beaten a lot of tough players this tournament".