49ers HC Kyle Shanahan: 'The way the defense played' against Seahawks was 'unbelievable'

San Francisco's defense appears to be peaking for the stretch run. 

The 49ers' first-ranked scoring unit again showed out on Thursday night, overcoming a third-quarter offensive lull by holding steady in its domination over the Seattle Seahawks to help deliver a 31-13 victory.

"The way the defense played tonight was unbelievable," head coach Kyle Shanahan said after the game. "To keep them out of the end zone the whole game. The six sacks. The way I thought our corners played on the outside. Just a real impressive game, and we're real excited to watch it."

Seattle found itself overwhelmed in all three phases at first, surrendering a score to San Francisco on every other drive of the 49ers' eight first-half possessions. Christian McCafrrey accounted for two of those scores on 1- and 8-yard touchdown runs, and totaled 104 yards through two quarters.

The defense packed an even stronger punch, holding the Seahawks to 56 yards in the first half while allowing just three first downs and three points on Seattle's first six drives. Even the special teams delivered a fumble recovery on a muffed punt.

By halftime, the 49ers held a 24-3 lead and a 22:31 to 7:29 discrepancy in time of possession.

But this was a divisional battle, with the NFC West lead on the line and the two clubs separated by a single game in the standings.

The Seahawks cut into the lead three and a half minutes into the third quarter with a tipped pick-six by Jordyn Brooks, bringing the Seattle crowd to a frenzy that coincided with a quieted San Francisco offense.

The Niners would take over 22 second-half minutes to score again. Their defense found no such slump.

Although the Seahawks managed a 78-yard drive that stalled for another field goal to bring the score to 24-13,