The World number one beat Croatian Donna Vekic 6-3 4-6 7-6 (7-4) at the Porsche Tennis Grand Prix.
Osaka will now face Anett Kontaveit, who was able to progress after Victoria Azarenka retired.
Petra Kvitova will face Kiki Bertens in the other semi-final.
Pogacar wins third Flanders crown but faces fine for running red light
Tadej Pogacar has clinched a record-equalling third Tour of Flanders title on Sunday, but the Slovenian could face a fine from local authorities after running a red light at a railway crossing.
Thuram and Martinez star as Inter dismantle Roma
Inter Milan delivered a ruthless attacking masterclass to dismantle AS Roma 5-2 at home on Sunday, tightening their grip on the Serie A title as Marcus Thuram and Lautaro Martinez spearheaded the rout.
Silva to exit Man City at end of season, assistant manager confirms
Manchester City captain Bernardo Silva will leave the club at the end of the season, assistant manager Pep Lijnders confirmed on Sunday.
Penalty heroics help Leeds beat West Ham to reach FA Cup semis
Leeds United goalkeeper Lucas Perri saved two penalties as they edged past West Ham United 4-2 in a shootout, after their FA Cup quarter-final tie ended 2-2 after extra time.
Pogačar wins Tour of Flanders for record-equalling third time
Tadej Pogačar won the Tour of Flanders for a third time on Sunday, cementing his place among cycling’s all-time greats with another dominant performance.
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