Pliskova has spent more time on court than any other player at this tournament despite a first-round bye and was once again dragged into a long contest by a dogged Vekic.
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.
She will face world number eight Pliskova in the final after the Czech outlasted Croatia's Donna Vekic 6-2 4-6 6-3 in a topsy-turvy match that lasted over two hours.
"I knew that once I hit any short ball or any ball without that much speed, she was going to try to go for it".
"I knew I had to play good to win today", said Bertens.
Seahawks Week 3 Player of the Game: Safety Earl Thomas
But he had a costly fumble early in the fourth quarter deep inside Seahawks' territory that cut short a potential scoring drive. Carson finished with 102 yards, the first Seattle running back to top 100 yards since late in the 2016 season.
The frustration boiled over when Osaka double faulted in the ninth game of the second set to set up Pliskova's second break.
Pliskova broke once in each set in the decider, while Osaka - whose 10-match winning streak came to an end - was unable to set up a break-point opportunity.
Osaka also finished 2nd in the tournament in 2016.
The U.S. Open champion, who upset Serena Williams in the final in NY, overpowered her unseeded opponent and will face fourth-seeded Karolina Pliskova in Sunday's final. Two years ago, Osaka lost in the final to Caroline Wozniacki, this year's top-seeded player who was eliminated by Camila Giorgi in the second round.
In clinching the title, Pliskova took a big step towards securing her spot at the season-ending WTA Finals in Singapore, the victory putting her just ahead of Kiki Bertens for the eighth and final berth in next month's field.
Tiger Woods wins first tournament in 5 years
And an awkward one for the tour. 15 and 16, but a par save on No. 17 sent him to the final hole, a par-5, with a two-shot lead. Rose, on the other hand, won the FedEx Cup and a $US10 million ($13.7 million) payday, with Woods finishing in second spot.
Despite being encouraged by the sold-out crowd at Tachikawa Arena, Osaka wasn't able to stage a comeback. "I've literally never felt more exhausted in my entire life", Osaka said.
"Because if you set a really high goal, than normally, for me at least, I tend to overwhelm myself".
Playing her fourth final of 2018, the second-seeded Dutchwoman reeled off the final six games to emerge with a 7-6 (2), 4-6, 6-2 victory in a roller-coaster match lasting 2 hours and 24 minutes. To be holding this trophy feels special. "So I just wanted to be patient and wait for my chances", Pliskova added after capturing her 11th career WTA title without offering up a single break point.
Both players are in the top 10 in terms of number of aces served on the tour this year.
Oil prices at highest levels in 4 years
But a meeting of OPEC and non-OPEC energy ministers in Algiers ended without any formal recommendation for a supply boost. That suggests OPEC's power to influence the market will be tempered by US production for about another decade.