Among the worst defensive teams in the league earlier this season, the Chiefs had shown dramatic improvement the last three games, allowing an average of just 14.8 points. Those impressive performances came against Oakland, San Francisco and Buffalo.
"We didn't do as well as we've been in the past," Chiefs Coach Dick Vermeil said. "I felt that we've improved but we didn't show it today. They threw whenever they had a one-on-one situation. We just couldn't sack Hasselbeck. He did a heckuva a job getting out of sacks."
Hasselbeck completed 25 of 36 passes. Robinson had eight catches for 168 yards and two touchdowns and Alexander rushed for 145 yards and a pair of scores.
"There were opportunities to make plays and I tried to give our athletes a chance to make those plays," said Hasselbeck, who has been the target of criticism since being acquired by Seattle prior to last season.
"He has played pretty well I think," Seahawks Coach Mike Holmgren said. "But all and all, I think he's improved and is a better player than he was last year. Today, I think he was sharp. He had a good day today."
The Seahawks (4-7) needed the big offensive days to overcome a huge afternoon by Holmes, who accounted for 307 total yards and three touchdowns.
Holmes rushed for 197 yards and two touchdowns and had seven catches for 110 yards and a score. His four-yard touchdown run on the first play of the fourth quarter gave him 20 on the season, breaking the club record, set by Abner Haynes in 1962.
Holmes also took over the league lead with 1,209 yards rushing on the season.
"One of the things we're going to learn from this game is that whenever you get a team that is down, you can't give them an opportunity to come back like they did," Holmes said. "We have to come up big in the second half, and we didn't do it today."
Despite Holmes' huge game, the Chiefs (5-6) squandered a chance to move over the .500 mark.
The teams combined for 1,086 total yards and an NFL-record 63 first downs. It was also a single-season record equaling 13th game in the league this year with at least 70 points. Five of those games have involved Kansas City.
With their defense ravaged by injuries, the Seahawks had no answer for Holmes, who had a 15-yard touchdown run early in the first quarter and 64-yard touchdown catch on a screen pass midway through the second, giving Kansas City a 17-7 lead.
But the Seahawks scored on their next four possessions, starting with Hasselbeck's two-yard touchdown pass to fullback Mack Strong with 2:26 left in the half.
The Seahawks' defense followed by coming up with the play that turned around the game with 59 seconds left in the half.
Kansas City had a first and goal at the Seattle one. But instead of a handoff to Holmes, the Chiefs called a passing play and Trent Green was intercepted in the back of the end zone by linebacker Orlando Huff. The play was initially ruled to be incomplete, but was changed by replay.
"I'm always going to be competitve and wanted to contest the call," Huff said. "When I looked up at the screen, it looked like I had two feet in. The call got turned over and it was good for us to get off the field."
Hasselbeck then went to work, needing eight plays to drive the Seahawks 80 yards. He had a 19-yard run to the Kansas City 45 and a 29-yard completion to Darrell Jackson to the six.
"When he (Holmgren) called the deep passes, I was really excited," Hasselbeck said. "And it gives me confidence when they call a pass in a critical situation and they're willing to put the ball and game in my hands."
Hasselbeck capped the drive with six seconds left in the half, lofting a pass to the left corner to rookie tight end Jerramy Stevens, who made a diving catch just inbounds, giving the Seahawks a 21-17 lead. It was Stevens' first career touchdown.