Wozniacki's frustration arose in the seventh game of the opening set when she twice slammed her racquet into the net after losing a point. The 27-year-old won the Rogers Cup in 2010 at Montreal, one of 25 career titles.
Wozniacki, a former world No. 1, is 0-5 in final appearances this season.
Pliskova, meanwhile, will move on to play sixth-seeded Caroline Wozniacki of Denmark, who ousted 10th-seeded Agnieszka Radwanska of Poland 6-3, 6-1. Despite the defeat in this year's final, Wozniacki was staying upbeat, preferring to focus on the positives from what was overall a great week. She smashed her racket into the court when another miscue gave Wozniacki a 6-5 edge. This last has easily defeated the Romanian Simona Halep in two identical sets of 6-1.
Halep, who advanced to second on the world ranking, has seemed to lack energy, winning just 43 percent of his first balls-of-service, compared to 84 % for her rival, who also racked up two aces. It's just tough to play her in these conditions.
The second set somehow remained on serve, with the Czech first seed saving four break points in the fifth game.
"It's unbelievable that I achieved this, but I try to take one tournament at a time, to not think so much about all the past titles", Svitolina said. Halep will be left pondering a mental game that still needs work, but Svitolina is no doubt delighted at the chance to win her third Premier Mandatory/Premier 5 title of the season. She then held serve and followed with another break to lock up a spot in the final four. However, she is now winless in six championship matches this year. The Ukrainian player won again, in the final in straight sets. The other match was in the 2016 Miami Masters, which was decided in three sets.
The match ended just over five hours after the players took to the court in the early afternoon for the pregame warmup. However, conditioning and fatigue isn't on Svitolina's side. In the quarterfinals the next day she beat Wimbledon champion Garbine Muguruza in a grueling three-set match.
"She just put everything back", Pliskova said.
"It was a tough day", Wozniacki said.
It won't be easy, but rest is on Wozniacki's side, which is key in a match that could be tight.