"We faced some adversity, but I think it says a lot about our offense and defense," Grossman said, "because this is a tough place to play."
Antoine Winfield returned one of Grossman's two interceptions for a fourth-quarter touchdown, and Ryan Longwell 's third field goal with 7:27 remaining gave Minnesota a 16-12 edge. But Chester Taylor coughed the ball up with 3½ minutes left and Adewale Ogunleye recovered at the Vikings' 37-yard line, setting up Grossman's first career fourth-quarter scoring pass.
"The past few weeks, we've been grinding down teams in the fourth quarter. It just worked the other way this time," said Taylor, referring to 19-16 and 16-13 wins by Minnesota over Washington and Carolina.
The Bears, undefeated, are still in charge of the NFC North.
This was the first Metrodome victory since 2001 for Chicago, which committed 10 penalties for 82 yards and looked beatable until the end. Robbie Gould kept the Bears in it by kicking four field goals.
The Vikings (2-1) got the ball back with 1:45 left, but failed to convert a first down. Brad Johnson 's up-the-sideline heave on fourth-and-2 at his own 46, with Ogunleye in his face, was thrown well past Troy Williamson.
Chicago's always-active defense, which allowed the league's fewest points and finished second in yards given up last year while winning the division with an 11-5 record, was plenty good.
The offense, despite Grossman's obvious struggles with a heavy pass rush, did what it had to do in the clutch, too. After missing big chunks of the past two seasons because of injuries, Grossman has thrown for 829 yards and helped guide the Bears to their first 3-0 start since 1991.
"We really believe in him," center Olin Kreutz said. "We think he's that good."
Grossman completed 23 of 41 passes for 278 yards and the late touchdown. Muhsin Muhammad caught nine balls for 118 yards, and Thomas Jones rushed 19 times for 53 yards.
Minnesota, now playing the same Tampa Two zone defense that Chicago coach Lovie Smith installed, got heavy pressure on Grossman and effectively used a mixture of blitzes. Winfield and Darren Sharper each had their hands on balls that should have been interceptions, and the Vikings forced field goals on consecutive third-quarter drives that reached the 6 and 12-yard lines.
"This does a lot for the confidence of the other members of the offense," Muhammad said. "Everybody knows that the ball can come to them on any given occasion, and that makes you play harder."
Minnesota still spoke with confidence, too, despite the late lapse.
"It's early in the season," Sharper said, "and we'll see those guys again."
The Bears' defense was not, however, outdone. Johnson was under constant pressure, and Taylor had his lowest rushing total, 74 yards on 20 carries, of the year.
"We were close to having what we wanted," said Johnson, who went 21 for 31 for 194 yards. "We've been in every game and won two out of three of them. Today hurts, but we'll move on."
Notes:
Smith (dehydration), G Steve Hutchinson (hamstring spasm) and CB Fred Smoot (concussion) all missed plays for Minnesota, but returned. LB Ben Leber (knee sprain) and G Artis Hicks (bruised knee) were also banged up. ... TE Desmond Clark (strained foot) left in the third quarter for Chicago. LB Jamar Williams (shoulder) and T John Tait (shoulder) were also hurt. ... Vikings coach Brad Childress, who cut his postgame remarks short after three questions, did not, however, address why rookie Cedric Griffin played in Smoot's place on the first defensive series.