The Seahawks were that close to dominating.

That close to a blowout before halftime. Still, they sent the message that the NFC West is theirs.

The Seahawks made a show of force in their dismissal of the Arizona Cardinals, a display that featured hard-hitting, constant pressure on the quarterback and big plays on offense.

And yet the Seahawks made just enough mistakes — and failed to make enough plays — to make it a tighter game than it should have been in their 21-10 win over the Arizona Cardinals on Sunday at Qwest Field.

Truth be told, for a few moments in the fourth quarter, the Cardinals were in striking distance. A touchdown drive would have made for some uneasiness among the Qwest Field faithful.

Alas, total misfortune did not come to pass for the home team. The Seahawks' defense came up with its second straight solid performance. The offense, if nothing else, was more productive than last week's win at Detroit, to the tune of 341 total yards and the first three touchdowns of the 2006 season.

But the mistakes and missed opportunities got their share of focus.

"We let too many things go," middle linebacker Lofa Tatupu said. "We're not that sharp right now."

Seahawks receivers dropped five passes. The defensive backs dropped two would-be interceptions. Penalties nullified three would-be Cardinals turnovers. And another week, another blocked field goal, as Josh Brown's 30-yard chip shot was easily dismissed after a shaky hold.

Those things had some Seahawks wondering what the score could have been.

"We thought we should have had at least nine turnovers in there," linebacker Julian Peterson said with a smile. "But you live and you learn. I think all the guys ... who had the opportunity to make a play are upset with themselves."

Wide receiver Nate Burleson, who juggled and dropped what might have been a first-down catch on third-and-19 in the first quarter and mishandled another pass in the third quarter, accepted responsibility for his actions.

"When the defense is doing such a great job, you're on the sideline thinking that maybe the score should be double what it is," Burleson said. "We did leave a lot of points on the field as an offense. Individually speaking, I dropped two big balls that could have helped some drives and we could've scored on those. You could say 14 points came off the fingertips of Nate Burleson."

What was a 14-0 Seahawks lead after their first two drives of the game could easily have turned into a rout. But there was the missed field goal — "I do not want that every time we try one, it be on the Discovery [Channel] station as one of the great adventures of all time," coach Mike Holmgren cracked — and a thrown interception by Matt Hasselbeck from the Arizona 30-yard line.

The Arizona defense also got stingier in the second and third quarters, forcing three three-and-outs.

Nevertheless, the Seahawks outplayed the Cardinals on both sides and made their breaks, with a little help from the 12th Man. The Cardinals had ample opportunities to produce, but they were stymied time after time until a 40-yard touchdown pass from Kurt Warner to Bryant Johnson early in the fourth quarter.

Eight offensive penalties (false starts, delay of game, holding and illegal motion) amid the noise at Qwest Field, and the confusion the Seahawks' defense caused, made for part of Arizona's undoing. Wide receiver Darrell Jackson was key with five catches for 127 yards and a touchdown, and Warner appeared to be ducking for cover or avoiding the Seahawks' rush — whenever he could — on every other play.

The Seahawks sacked Warner five times and logged 12 quarterback hurries.

The offense started hot, turned cold, and heated up again in time to seal the win. Fullback Mack Strong ignited the Seahawks' third drive in the second half. Strong converted a third down with a 13-yard run and later scored his first touchdown since the 2003 season to give the Seahawks a 21-3 lead with 14:22 left in the game.

"Those guys got a little bit more aggressive," Jackson said of the Cardinals. "We had the game kind of in control, and maybe we slacked off a little bit. Who knows? We scored enough points to overcome that momentum and win this game here."

José Miguel Romero: 206-464-2409 or jromero@seattletimes.com