Leinart connected with Larry Fitzgerald on a five-yard scoring pass, and Rackers was good from 40 yards, as the Cardinals came back from a 21-17 third-quarter deficit.
Leinart went 21-for-34 for 232 yards, two touchdowns and one interception. Edgerrin James carried the ball 26 times for 115 yards and one touchdown, and Bryant Johnson scored on a 56-yard catch for the Cardinals (4-9), who have won three of their last four games.
Matt Hasselbeck threw three touchdown passes, and Shaun Alexander rushed for 76 yards on 22 carries for Seattle. D.J. Hackett, Nate Burleson and Darrell Jackson all caught touchdown passes for the Seahawks (8-5), who had won their previous two games.
Arizona led, 14-7, after the first quarter, and held the Seahawks scoreless in the final quarter.