Japanese ace Yamaguchi served out Pornpawee Chochuwong of Thailand 21-12, 21-17 at New Delhi's Indira Gandhi Indoor Stadium.
Yamaguchi looked in supreme touch as she went past her opponent, who got a walkover in the quarter-final after Nozomi Okuhara pulled out due to a knee injury, in game one.
The second game was close but world number two Yamaguchi's experience held her in good stead to move into her fourth world championship final.
"I don't …