first championship win
Often used in sports, especially sumo, for a competitor's first tournament victory.
彼は今年の春場所で初優勝を果たした。
He achieved his first championship win at this year's spring sumo tournament.
The team is aiming for its first championship win since its founding.
He finally achieved his first championship win.
The rookie sumo wrestler celebrated his first championship win.
She won her first championship at this tournament.