German Kerber has not won a title since and will now drop out of the world's top 10.
Denmark's Caroline Wozniacki battled back after a mid-match slump to beat Angelique Kerber of Germany on Friday and book a place in the semi-finals of the Pan Pacific Open.
Pliskova, a finalist at last year's US Open who reached the semi-finals at Indian Wells last week, relied on her booming groundstrokes and strong returning to dispatch her American opponent in 59 minutes.
Russia's Svetlana Kuznetsova raced to a 6-2, 6-1 victory over Australian Daria Gavrilova to defend her Kremlin Cup title in Moscow on Saturday and secure a place at the season-ending WTA Finals.
China's Li Na overcame an attack of nerves and weathered a feisty challenge from Dominika Cibulkova before roaring to a 7-6 (7-3), 6-0 victory to win her first Australian Open title on Saturday.
Venus Williams' return to Indian Wells lasted just one match but sister Serena looked poised for a long run after a dominant win at the BNP Paribas Open on Friday. Venus returned to the event for the first time since 2001, having boycotted it after being booed and heckled by fans during her previous trip, but made a quick exit after a 6-4 6-3 defeat to Japanese qualifier Kurumi Nara in the second round. The 15-year-old incident had occurred when Venus withdrew from a semi-final match with Serena, drawing ire from the crowd aimed at the Williams family. This time, though, Venus was greeted warmly by the crowd before her match and throughout it, a consolation for her poor performance. "It was enough of a fairytale to come here and play," Venus told reporters. "A win would have been nice, but that means I have to come back, play next year."
The exodus of seeded players has been so spectacular that only one of the top 10 remains -- number seven Karolina Pliskova.
Top-seeded world number ones Serena Williams and Novak Djokovic help launch the US Open tennis championships on Monday's opening day of the year's final Grand Slam.
Maria Sharapova joined Serena Williams in making an early exit from the Australian Open on Monday but defending champion Victoria Azarenka swept into the quarter-finals with an 18th straight victory at Melbourne Park.
The absence of expectant mother Serena Williams and a failure by any of the other top women to produce the kind of dominance the American seven-times champion has consistently delivered makes this year's Wimbledon the most open in years.
He leads the men's seedings ahead of defending champ Roger Federer, with Bulgarian Grigor Dimitrov seeded third.
Serena Williams battered Anastasia Pavlyuchenkova 6-4, 6-4 in the quarter-finals at Wimbledon on Tuesday, seizing on moments of weakness from the Russian to ram home her advantage.
World number four Stan Wawrinka began the new season with a straight-sets victory over Viktor Troicki in his Brisbane International debut on Wednesday. Second seed Wawrinka edged out Troicki 7-6(5) 6-4 to maintain his perfect record against the Serbian whose seventh attempt at beating the Swiss failed at the Pat Rafter Arena. "I'm quite happy with my level at the start the year," Wawrinka said.
World number one Novak Djokovic received a free pass into the third round of the U.S. Open when Jiri Vesely of the Czech Republic withdrew from their match on Wednesday due to a left forearm injury. The walkover provided the top-seeded defending champion with an extended break to improve his niggling left wrist injury before his next match against either Guido Pella of Argentina or Mikhail Youzhny of Russia.
Bulgaria's Grigor Dimitrov edged out South Africa's Kevin Anderson 7-6 (7-1), 3-6, 7-6 (7-5) in a three-hour slugfest to claim his second career title with victory in the Acapulco International final on Sunday.
Serena Williams is playing at another level, says beaten Agnieszka Radwanska
Serena Williams edged past Spain's Garbine Muguruza 2-6, 6-3, 6-2 to reach the quarters.
Fourth seed Angelique Kerber's bid for consecutive Grand Slam titles ended when 29th seed Dominika Cibulkova defeated the German 3-6, 6-3, 6-3 in the US Open third round on Saturday.
Russia's Elena Vesnina ousted German second seed Angelique Kerber 6-3, 6-3 to reach the quarter-finals of the BNP Paribas Open at Indian Wells, California on Tuesday.
The 'Big Four' of men's tennis have made it into the second week of Wimbledon unscathed and largely untroubled while the women's draw remains wide open, but "Manic Monday" could offer major clues as to the destination of this year's titles.
The 24-year-old was staring at defeat while down a set and a break but dug deep to prevail in two hours 24 minutes for his 200th tour match victory and his 10th ATP title.
The fluorescent yellow outfit Victoria Azarenka wore as she dismantled Caroline Wozniacki at the Australian Open on Thursday was a one-word fashion statement -- loud.
Australian Nick Kyrgios was expelled from the tournament after going wild in the third set of his match against Casper Ruud.
Former world number one Garbine Muguruza was beaten 7-5, 6-4 by Aryna Sabalenka in the China Open second round on Tuesday while an ailing Jelena Ostapenko lost 6-0, 6-0 to Wang Qiang.
The 23-year-old Wimbledon champion, who climbed to the top of the WTA rankings on Monday, hardly broke sweat against the Frenchwoman, ranked 20th in the world, on her way to victory in an hour and 20 minutes.
The 25-year-old Dzumhur recovered from a poor start to beat the Briton 1-6, 7-5, 6-3 and will bid to become the Balkan nation's first Tour winner in Saturday's title-decider against Spain's Roberto Bautista Agut.
Maria Sharapova rallied to beat Kaia Kanepi on Thursday and will meet Serena Williams in the Brisbane International semi-final knowing she must drastically improve to end her run of 13 straight defeats against the world number one.
'Right now I think that I have to find to myself again and just trying to forget the clay court season as soon as possible'
The latest tennis rankings have been announced by the ATP and WTA
Tennis star Maria Sharapova said on Tuesday she is excited about her return to competition next month, feeling vindicated by the reduction of her doping suspension and empowered by her time away.
Johanna Konta earned the chance to fulfill a childhood dream when she advanced to an Australian Open quarter-final contest against Serena Williams by dismantling Ekaterina Makarova 6-1, 6-4 on Monday.
Angelique Kerber produced a polished display to claim her second straight win at the WTA Finals with a 6-4, 6-2 victory over Simona Halep on Tuesday, the world number one virtually booking a spot in the semi-finals of the elite eight-woman event.
Angelique Kerber showed more passion in the media centre than on the court when she crashed out of last year's WTA Finals, the German angered by the format and frustrated by her inability to win the set off an eliminated opponent she needed to advance.
Serena Williams underlined the difference in class and power between her and the rest of the women's field with a 6-0, 6-4 demolition of fourth seed Agnieszka Radwanska on Thursday to reach her seventh Australian Open final.
With a career Grand Slam of major titles and a sweet-making business, Maria Sharapova dismissed the idea of staying at home and having a drink.
Keys and Stephens to put friendship to grand slam test
It would be hard to bet against the Williams sisters meeting in their first Wimbledon final since 2009, but Angelique Kerber and Elena Vesnina won't just be making up the numbers in the last four on Thursday. While unseeded Vesnina has described her semi-final against world number one Serena Williams as a dream, she is playing inspired tennis, bringing the guile from two doubles slams to deliver baseline power and a deft touch at the net.
Serbia's Novak Djokovic is the top seed in the men's draw which includes five-times US Open champion and 17-times Grand Slam winner Roger Federer as seventh seed - his first time the Swiss has been placed outside the top three in a Grand Slam in over ten years.
The women's draw at the US Open has been in news for the upsets it created. Almost everyday one or some days even two of the top seeds feel to unknown players.
Former Wimbledon champion Marion Bartoli just wants to enjoy herself and play big matches when she returns to competitive tennis in March after more than four years in retirement.