Further review: Mathis' sack of Smith

Posted by ESPN.com’s Paul Kuharsky

The suggestion from mdcady80: Although Addai's throw to Wayne was indeed a game changer, the sack on Smith afterwards was much bigger. Alex Smith was leading a counter charge midway through the 4th quarter, leading the 49ers past midfield. On 3rd down, Smith goes back for a pass, and gets sacked by Dwight Freeney, taking them out of field goal range and giving Manning 5 minutes to wind the game down. If the 49ers pick up the first down, momentum builds and a field goal or touchdown is almost certain. The colts didn't get as much pressure as they would have liked, but that sack was very timely and changed the course of the game.”

The sack was actually by Robert Mathis and it wasn’t San Francisco’s last possession, but it was a giant play nonetheless.

The situation: San Francisco ball, third-and-2 from the Indianapolis 35-yard line with 11:49 to go in the game and the Colts ahead 18-14.

The 49ers line up three wide with Isaac Bruce wide left, Josh Morgan in the slot left and Michael Crabtree wide right. Vernon Davis is a couple yards off the left tackle, standing up. Frank Gore is to the right of Alex Smith, who’s in the shotgun.

The Colts have nickel personnel on the field.

What I saw unfold after the snap:

Linebackers Gary Brackett and Clint Session, who had crept close to the line of scrimmage before the snap, both peel out to help in coverage, Brackett with Jerraud Powers on Davis, Session to the middle.

Defensive tackle Raheem Brock also drops back into coverage, leaving a three-man rush with right end Freeney, tackle Eric Foster and left end Mathis.

Foster is single blocked by center Eric Heittmann and doesn’t gain any ground.

Freeney draws a double team from left tackle Barry Sims and left guard David Baas, who give ground but do well to stave him off.

Mathis puts a spectacular spin move on right tackle Adam Snyder, acting as if he’s going to rush inside and going from Snyder’s right shoulder to beating him outside his left shoulder in the blink of an eye. Gore runs through the line where Mathis started, offers no blocking help, turns to the right flat and doesn't get there quickly enough to be of service.

Smith drops three steps from where he takes the shotgun snap, and by the time he sets, Mathis is just two yards and one step to the side away. He gets a hand on Smith’s shoulder, another on his waist and drags him down for an eight-yard loss.

Result: The sack takes the 49ers out of field goal range in their only foray into Colts’ territory in the second half.

Ultimate outcome: Indy’s offense runs 17 of the game’s remaining 24 plays as the Colts hold on to remain perfect at 7-0.