SEATTLE (AP) -- With each completion, Matt Hasselbeck winced.
He needed electrical stimulation on his strained side muscle while he was on the bench, "some things to make it feel better" at halftime and "a lot of sympathy tonight when I get home," Hasselbeck said.
And, to think, this was a great day for the Seahawks' quarterback.
Hasselbeck continued perhaps the best season of his career with 30 completions for 337 yards and two touchdowns, and Seattle took advantage of Chicago quarterback Rex Grossman's late fumble to hold on for a 30-23 victory against the Bears on Sunday.
Hasselbeck thrived again using a wide-open shotgun offense that coach Mike Holmgren always resisted but has now embraced because of a stalled running game. He threw 44 times, tied his season high in completions and had his third 300-yard passing day of the season -- his most in three years -- as Seattle (6-4) maintained its one-game lead over Arizona in the NFC West.
"It's so much easier. At times you feel like it's cheating," Hasselbeck said of the shotgun, which is more a pistol because he lines up just a few yards behind center. "When they blitz, just catch and throw.
"It's nice. It's really nice."
Hasselbeck's best throw was also his most improvisational one. On third-and-goal at the 4 early in the third quarter, he ran toward the line to avoid defensive end Alex Brown and suddenly flipped a low pass that Nate Burleson caught inside the goal line, the receiver's legs split and his right knee on the ground. That put Seattle ahead 24-17 and left Brown punching the turf in frustration.
Hasselbeck set up that score by converting a fourth-and-inches with a 20-yard bootleg pass to Marcus Pollard. And he began Seattle's 14-point answer of a 10-0 deficit in the first quarter with a 19-yard touchdown pass to D.J. Hackett.
Hackett set career highs with nine receptions for 136 yards.
For 3 1/2 quarters, Grossman was efficient in his return as the Bears' starting quarterback after watching Brian Griese run the offense for six games. Grossman was 24-for-37 for 266 yards -- his most since he threw for 282 last January in a win against Seattle in the NFC divisional playoffs.
But after not turning the ball over all day, Grossman made the mistake that Bears (4-6) followers seem to expect from him, with 5:43 left.
After throws of 22 yards to Muhsin Muhammad and 23 yards to Bernard Berrian -- a terrific, one-handed catch -- got the ball into Seattle territory with Chicago down 27-20, Grossman could not find an open receiver. He took off running. Patrick Kerney caught him from behind and ripped the ball from his right hand. Darryl Tapp recovered the fumble at the Seattle 47.
The Seahawks turned that into Josh Brown's clinching field goal from 46 yards with 3:36 remaining.
"I was in range for the sack. I figured I might as well wait. I was just waiting for him to show the ball," said Kerney, who got three of the Seahawks' five sacks -- all in the second half.
Seattle has 28 sacks in its six wins. It has three sacks in its four losses.
Grossman, who has lost three of his four starts this season, wasn't eager to rate his return performance.
"At this point I have too many things running through my head to pinpoint anything," he said, angrily. "The biggest frustration about this game is that we had our chances to win it against a pretty good team in a hostile environment.
"That's all. That's all I've got to say."
When asked if Grossman will start again at home against Denver next weekend, coach Lovie Smith said: "We handle it week to week and I won't make any statements about that right now.
"But I was definitely pleased with how Rex played at the quarterback position. I thought it gave us a chance to win."
Chicago has more problems than Grossman. The defense, often dominant in the Bears' run to the Super Bowl last season, allowed 425 yards -- including 87 on 18 carries by Maurice Morris. Morris scored a touchdown while starting for the second consecutive game for the injured Shaun Alexander.
The Bears allowed 30 points for the fourth time in 10 games. Chicago allowed 30 points in just three games over the previous two seasons.
"Got to play better. Too many yards," is all linebacker Brian Urlacher spat out.
Chicago was poised to retie the game midway through the third quarter when Berrian caught a pass from Grossman and reached for what was initially ruled a first down. Seattle challenged the spot, and a replay review reversed the ruling, leaving the Bears with a fourth-and-1. Cedric Benson ran up the middle behind fullback Jason McKie, but Lofa Tatupu leaped over a blocker and stuffed Benson for no gain.
Benson gained 89 yards on 11 carries. He ran 43 yards for a touchdown on Chicago's second play. Then his 20-yard run set up Robbie Gould's 31-yard field goal. Benson's longest run among his first 178 carries this season was 16 yards. ... Seattle threw on 15 of its first 17 plays.