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.
Bergs shocks Alcaraz in Shanghai as Zverev claims year-end top ranking
Seven-times Grand Slam champion Carlos Alcaraz suffered a shock 7-5 7-6(4) defeat by unseeded Belgian Zizou Bergs in the Shanghai Masters round of 32 on Monday, a result that also confirmed Alexander Zverev as the ATP's year-end world number one.
Ten arrested and police officer injured after Manchester City’s win at Liverpool
Ten people were arrested and a police officer suffered a serious facial injury after crowd trouble at Manchester City’s 3-0 Premier League win at Liverpool on Sunday, Merseyside Police said on Monday.
Australia stretch lead to 280 against South Africa in first Test
Australia extended their lead over South Africa to 280 runs but lost four wickets in reaching 174-4 at lunch on the fourth day of the first Test in Durban on Monday.
Red Bull's Verstappen wins Singapore Grand Prix
Red Bull's Max Verstappen has delivered a commanding performance to win the Singapore Grand Prix from pole position on Sunday, securing his second straight victory of the season after a perfect weekend that included a sprint race triumph.
Blades Brown, 19, becomes youngest to earn PGA Tour card via Korn Ferry Tour
Blades Brown has finished second to Austin Hitt at the Korn Ferry Tour Championship on Sunday in Glen Allen, Virginia, to lock up his PGA Tour card at just 19 years and four months old
