The Seahawks were on the verge of at least cutting into the 49ers 23-17 lead with the ball deep in San Francisco territory.
But after a turnover from a strip-sack, Seattle was held off the board. Instead, the 49ers went down the field to increase their lead to 31-17 in the fourth quarter.
late in the third quarter on third-and-14 from the San Francisco 19, quarterback Geno Smith had the ball knocked out of his hands in the pocket by defensive lineman Charles Omenihu. Edge rusher Nick Bosa picked up the loose ball to give San Francisco an extra possession — and keep Seattle points off the scoreboard.
A couple of plays later, Purdy escaped the pass rush to find running back Elijah Mitchell wide open in the flat. Mitchell caught the pass and easily got into the end zone for a 7-yard touchdown.
San Francisco elected to go for two, and Purdy hit tight end George Kittle for a successful conversion.
Smith’s fumble was the first turnover in the game for either team and was certainly costly.
The Seahawks will have to mount a significant comeback in the fourth quarter to beat their division rival.