Complex sentence: Chicago's first Stanley Cup was later won against the Red Wings in 1934, when winger Mush March scored a goal in a double-overtime game, the first-ever Stanley Cup-winning overtime goal in the history of the NHL.
Split into simpler sentences: Chicago's first Stanley Cup was won versus the Red Wings in 1934, when winger Mush March scored a goal in a double-overtime game. This was the first Stanley Cup-winning overtime goal in the history of the NHL.