Kerber improved her record over Pliskova to 7-3 after winning five of their last six matches against her fellow former WTA number one. Kerber, ranked ninth after a solid start in 2018, claimed her 15th win of the season, pulling her level for the lead on the WTA circuit with number one Caroline Wozniacki.
Pliskova was playing her first Dubai quarter-final since finishing runner-up three years ago. Kerber reached the final four in an hour and a quarter with three breaks of serve without facing a challenge to her own serve.
Svitolina ended a run of two 2016 losses to Osaka, ranked 48th and first Japanese quarter-finalist at the event since 2004.
In another quarter-final second seed Garbine Muguruza beat fifth seed Frenchwoman Caroline Garcia 7-5, 6-2. The two-time Grand Slam winner is seeking her first title since Cincinnati last August and next faces Daria Kasatkina, who beat fellow Russian Elena Vesnina 7-6 (5), 6-1.
Sock, Isner and Raonic
lose at Delray Beach Open
Top seed Jack Sock, John Isner and Milos Raonic all exited on a day of upsets at the Delray Beach Open in Florida on Wednesday.
Two months after clinching his first Masters 1000 title in Paris, Sock was in less stellar form, beaten 4-6, 7-5, 6-3 by fellow American Reilly Opelka in the second round.
Isner came out on the wrong end of three consecutive tiebreaks against German Peter Gojowczyk, who prevailed 7-6(3), 6-7(4), 7-6(5). Raonic was beaten more comprehensively, outplayed 6-2 6-4 by American Steve Johnson, who earned his first ever victory over the Canadian.