''He successfully ran the offense,'' Seattle cornerback Richard Sherman said. ''He got them down the field, he made some great decisions in terms of running and passing the football. Obviously, there were some mistakes in there as well. But to come off the bench and beat the Falcons, it was a great performance.''
Gabbert finished with 185 yards on 15 of 25 completions with two touchdowns and two interceptions. He was effective with his legs, running for 32 yards on eight carries, including a designed 5-yard run just outside of two minutes remaining for a first down that helped seal the win.
This week, Gabbert's test is drastically more difficult in a stadium considered one of the toughest on visiting teams.
''It's going to be loud, we know that,'' Gabbert said. ''In these stadiums where it is extremely loud, you really have to focus one play at a time because if you don't hear a call, you don't hear the play, one or two guys aren't going to be on the same page and that's the difference between winning and losing games.''
Despite the 4-5 record, the Seahawks still boast the league's second-ranked defense in both total yardage and passing yards.
Since the win over Atlanta, Gabbert had a bye week to become more acclimated to his new role as starter after the struggling Colin Kaepernick was benched.
In Kaepernick's last three starts against Seattle, the 49ers were outscored 56-13 while he failed to throw a touchdown pass, including in a Oct. 22 loss at Levi's Stadium, 20-3.
The previous time the 49ers beat the Seahawks on the road, their starting quarterback was Alex Smith, who Kaepernick replaced midway through 2012 before leading his team to a Super Bowl appearance.
Kaepernick hasn't played up to lofty expectations this season. Prior to his benching, the 49ers' offense ranked last in both yardage and scoring by significant margins.
Given the way the league operates, Sherman isn't surprised he won't be going against Kaepernick on Sunday.
''Football's a crazy game,'' Sherman said. ''It's who's playing well at the time, at the end of the day. Who would have thought when they were playing well and Alex Smith was out there, that a year later Alex Smith would be gone from San Francisco and Colin Kaepernick would be their guy? Things like that happen in football and you just got to roll with the punches.''
49ers coach Jim Tomsula would not commit to Gabbert as the starter beyond Sunday's game, leaving open the possibility of Kaepernick returning to the lineup.
''I liked the way (Gabbert) handled the game. I liked the way he played the game, and I want to move forward with Blaine and we'll go from there. That's all I have for you going into this game,'' Tomsula said.
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