kinboshi; win of a low-ranked wrestler over a yokozuna
Sumo term: a victory by a maegashira (rank-and-file wrestler) over a yokozuna (grand champion). Considered a major upset and a career highlight.
A maegashira wrestler defeated the yokozuna and earned a kinboshi.
dazzling victory; major upset; remarkable win
Figurative extension from sumo: a stunning victory against a much stronger opponent, often in sports, business, or other competitive contexts.
The rookie pulled off a major upset by beating the tournament favorite.
A rank-and-file wrestler scored an upset win over the yokozuna.
The yokozuna ended up allowing the up-and-comer a kinboshi.
The startup scored a stunning upset win against the industry giant.
The unknown player entered the match aiming for a stunning upset.