Buffalo (7-2) matched its best record through nine games since 1993, a season that ended with the Jim Kelly-led Bills making their fourth consecutive, and final, Super Bowl appearance.
Allen finished 31 of 38 and equaled a career best set earlier this season with 415 yards passing, becoming the first Bills player to top 300 yards four times in one season since Drew Bledsoe did it seven times in 2002. The Bills offense came alive after Allen combined for just 846 yards passing and five touchdowns — including one rushing — in splitting the previous four games.
The Seahawks (6-2) blew an opportunity to match to match their best record through eight games.