Rookie Brock Purdy threw two touchdown passes to tight end George Kittle and the San Francisco 49ers clinched the NFC West title with a 21-13 victory against the host Seattle Seahawks on Thursday night.

The 49ers (10-4) won their seventh consecutive game to take a three-game lead over the Seahawks (7-7) with three games to play in the regular season. San Francisco swept the season series to clinch the tiebreaker should the teams finish tied.

Purdy, making his first career NFL road start, completed 17 of 26 passes for 217 yards.

The 49ers' Christian McCaffrey rushed 26 times for 108 yards and a touchdown and added 30 yards on six catches. Kittle made four receptions for 93 yards.

Seattle's Geno Smith was 31-of-44 passing for 238 yards and a touchdown.

Trailing 21-6, Smith hit tight end Noah Fant with a 10-yard scoring strike with 3:35 remaining.

But the 49ers were able to run out the clock.

Purdy completed all nine of his pass attempts in the opening quarter as the 49ers took a 7-0 lead. Purdy faked screen passes to both his left and right before hitting Kittle over the middle for a 28-yard TD with 3:49 left in the first.

Jason Myers' 38-yard field goal pulled the Seahawks within 7-3.

Seattle got the ball back with less than two minutes left in the second quarter when Smith dumped off a pass to backup running back Travis Homer, who was sandwiched by Jimmie Ward and Dre Greenlaw -- with Greenlaw knocking the ball loose. Charvarius Ward recovered the fumble and returned it 40 yards to Seattle's 6-yard line.

McCaffrey scored from 1 yard out two plays later to give the 49ers a 14-3 halftime lead.

San Francisco took the second half kickoff and, on its second play from scrimmage, Purdy hit a wide-open Kittle down the left sideline and he avoided two defenders for a 54-yard TD.

Myers' 51-yard field goal midway through the third made it 21-6.

San Francisco's Deommodore Lenoir, who made a team-high 10 tackles, had a pick-six in the third quarter wiped out by Nick Bosa's roughing-the-passer penalty.

--Field Level Media