Few could have predicted what was to come when Pliskova started her match full of controlled aggression against an erratic Stephens as the Czech rattled through the opening set in 31 minutes.
The games were getting longer as the intensity levels increased and the pair traded breaks early in the second set until Kerber's form dipped when she was broken in the eighth game and the American gleefully raced away to seal victory.
"It feels awesome, it was such a tough battle and I'm very happy I could win in the end", she said.
"There were nerves early on but I was just trying to fight for every ball and I think that made the difference in the end".
"I think the four of us, in our groups, we all played really well", Stephens said of the semi-finalists. "I was just happy to close it out", Svitolina said in a post-match interview.
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The first package addressed to CNN arrived Wednesday morning in the mailroom at Time Warner Center, home to CNN's NY offices. The FBI said the package was "similar in appearance" to the 14 pipe bombs that prompted a federal investigation last week.
"Then I lost that second game in the third set where I was just struggling a little bit but bounced back straightaway".
"I worked on my mental toughness and that's pretty much what helped me to go through the (Caroline) Wozniacki match and today's match", added Svitolina, who won all three group ties but needed to take a set off the Dane to ensure qualification to the semi-finals.
"I don't think I did that many things wrong in the second set", she said.
"It's definitely a good statement for myself and good boost of - I can't say confidence, because I try to always have confidence in myself, to have it is my personality".
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Penitentiary Hazelton in West Virginia after being transferred from an Oklahoma City prison on Tuesday (October 30). He went on the run with his girlfriend Catherine Greig, ending up in Santa Monica, California .
The Dutch world No. 9, who was runner-up in last year's doubles competition with Sweden's Johanna Larsson, has 12 victories over players ranked in the top 10 this season, the most by any player since Serena Williams in 2014.
Svitolina was on a mission to silence the "haters" this week and she should have won plenty of new admirers after taking on all comers to claim the biggest title of her career.
The match started tensely, with Kerber unable to convert seven break points in Stephens´ first three service games, and the missed opportunities proved costly. Next year the tournament will be happening in the Chinese city of Shenzhen.
Svitolina has looked on a mission at the WTA Finals in an effort to make amends for a lacklustre early exit a year ago.
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"The Butler High School community and CMS appreciate the support of the entire community during this hard time", said the post. Cuffie is in the ninth grade at Butler High School. "[CMS] is really going to have to look at security", she said.