Dave Krieg threw a club-record five touchdown passes today and the Seattle Seahawks, who backed into the playoffs earlier in the afternoon, moved into sole possession of first place in the AFC West with a 38-17 victory over the Detroit Lions.

The Seahawks (12-2) have won eight straight. They learned they had qualified for the playoffs for the second straight year when New England's loss was announced during their first quarter. Then Denver, which began the day tied with Seattle for first in the AFC West, lost to Kansas City.

Krieg, whose 29 touchdown passes put him second in the NFL behind Miami's Dan Marino, broke open a 21-17 game with a 51-yard touchdown throw to Daryl Turner with 1:43 gone in the last quarter.

The Seahawks, 19-6 since Krieg became a starter midway through last season, then drove for a 36-yard field goal by Norm Johnson with 5:06 gone in the last period. That came after Ken Easley picked off Gary Danielson's pass and returned it nine yards to the Lions' 38. It was Easley's ninth interception, most in the NFL.

With 6:57 left, Krieg got his fifth touchdown pass, a five-yarder to tight end Mike Tice in the end zone.

He also threw 13 and three yards to Steve Largent for touchdowns in the opening half and four yards to Turner 36 seconds before halftime to give their team the 21-17 lead.

"He's gotten better with every game he's played," veteran guard Reggie McKenzie said. "I'm just sorry I won't be around for several more years to play with him, because he's going to get a lot better."

Krieg completed 27 of 38 passes for 294 yards with one interception before Jim Zorn relieved him late in the game.

Danielson was 11 of 20 passing for 117 yards before being replaced by rookie John Witkowski, from Columbia, in the last quarter.

The Seahawks' defense, which had its problems the first half, blanked the Lions the last 30 minutes. Detroit (4-9-1) has lost five of its last six.

In the final quarter, the Seahawks sacked Witkowski five times for 35 yards, end Jeff Bryant getting three for 19 yards. Danielson was not sacked.

Krieg's third touchdown pass, the four-yarder to Turner, ended an 80-yard, 13-play drive, all of it through the air. It came after the Lions scored their second touchdown of the second quarter, on Danielson's 15-yard pass to James Jones 3:09 before intermisssion.

Detroit got a 45-yard field goal from Ed Murray with nine seconds left in the first quarter and a 25-yard touchdown run by Ken Jenkins with 1:59 gone in the second period.

Krieg's second touchdown pass to Turner broke the backs of the Lions. Turner caught the ball on Detroit's seven, behind cornerback Bruce McNorton. The defensive back went sprawling in an attempt to pull down Turner, who has caught nine touchdown passes his first year out of Michigan State.