Karolina Pliskova won her biggest title and denied Angelique Kerber the world number one ranking with an emphatic 6-3 6-1 victory in Sunday's final of the Western & Southern Open in Cincinnati.

The 15th-seeded Czech registered her sixth career title and second this year, following a win at Nottingham, with her total demolition of the second-seeded Kerber.

Pliskova, who leads the WTA Tour in aces, hammered home seven aces, the last one securing her stunning victory over the 28-year-old German, who had so much on the line.

"Of course I'm disappointed, but still she played a great match and a great tournament and deserved the win," Kerber told ESPN.

Kerber, who committed 32 unforced errors, most coming from her forehand, was on the podium last Sunday accepting the silver medal after falling to Puerto Rico's Monica Puig in the women's final at the Rio Olympics.

"I'm really tired," she said. "I played the 11th match in 13 or 14 days. I really enjoyed the week. I really tried my best today, but sometimes you have days when it's not working so good.

"I will try to maybe get another chance, go in fresh to the US Open, she said about the year's last grand slam tournament, where she will again have a chance to dethrone Williams.

Kerber seemed out of sorts from the start, while Pliskova looked comfortable and quickly found the range with her big forehand.

The German was broken in the first game at love and lost her next serve in falling behind 4-0. Kerber rallied to draw within 3-4 after a service break in the sixth game but Pliskova won the next two games to end the set.

Pliskova, 24, broke Kerber again in the second game of the second set and dominated the rest of the way.

It was the first premier tournament victory for the tall, slender Czech, who trotted over to hug her coach after the match.

"Angie played an amazing week and I think the whole year she's doing a great job," Pliskova said at the trophy presentation after registering 24 winners against 16 errors and saving four of five break points she faced.

"I know she was playing for the world number one. I think you deserve to be No. 1," she added. "But maybe next time."

The result allowed Serena Williams to push her reign on top of the rankings to 184 consecutive weeks, two weeks away from tying the all-time mark held by Steffi Graf.