The Indianapolis Colts’ penchant for timely defensive plays began with heroics from one Pro Bowl star and ended with another.

In between, there were just enough to save a Sunday as the Colts edged San Francisco 18-14 at Lucas Oil Stadium.

“This is what we live for,” said safety Bob Sanders, whose first-quarter interception led to a field goal. “You want to be on the side of the ball where you’ve got to make the stop to win the game.”

The Colts blanked the 49ers in the second half. Ahead by four points in the final quarter, Robert Mathis and Dwight Freeney stopped drives with sacks. Freeney’s third-down tackle of quarterback Alex Smith with 5:57 remaining proved to be the clincher.

“We want to be out there making big plays when it counts,” Freeney said. “Put it all on our shoulders.”

Despite playing fewer snaps due to a sore right knee, Freeney notched a sack in his eighth consecutive regular-season game to tie Mathis’ 2005 team record. Freeney faced mostly double teams but was in the perfect position when Smith tried to scramble and ran into him.

“It was a fight. It was definitely a fight,” Freeney said. “This game kind of took on the personality of their head coach.”

The props were for 49ers coach Mike Singletary, a former two-time NFL Defensive Player of the Year and one of the nastiest middle linebackers when he played for the Chicago Bears from 1981-92.

“We came here to win a football game, bottom line,” Singletary said.

The 49ers announced those intentions with an early attention-getter, too, as Frank Gore squirted through a hole that seemed snug and broke through converging Colts tacklers Jerraud Powers and Antoine Bethea for a 64-yard touchdown run just 3:44 into the opening quarter.

“That was a nasty uppercut he gave us,” Mathis said of the longest scoring rush allowed by the Colts since Houston’s Steve Slaton went 71 yards on Nov. 16, 2008.

Down 7-3, the Colts needed something to change the momentum. Sanders, like Freeney, was in the right place at an opportune time. Smith’s pass was tipped by Michael Crabtree and fluttered directly to Sanders, who was making his second start since coming back from offseason surgery on his right knee.

“We’ve been overpowering teams for the past few weeks,” said linebacker Clint Session, who had a team-high eight tackles. “To still know that we’ve still got the fight in us, when it’s time to fight we can fight, it shows the heart of our team.”

A Colts defense that still gets overshadowed by Peyton Manning and the offense became the NFL’s best in fewest points allowed after this game. The Colts have given up 91, five fewer than previously undefeated Denver.

But the 49ers had a 14-9 halftime lead because Smith drove his team with stunning ease for a score in the two-minute offense.

“We were a little (upset) because we know we’re better than that,” Mathis said. “That’s supposed to be our time.”

The Colts made the second half their time as Powers came up with a Crabtree fumble in the third quarter. Then Mathis had the first clutch sack down the stretch.

The 49ers were facing third-and-12 at the Colts 35 and, at the very least, were within kicker Joe Nedney’s field-goal range. But Mathis dropped Smith for an 8-yard loss to force a punt.

“You get a sack like that, on third down, those are drive killers,” Mathis said. “They were going in. They had a full head of steam. If you can get a good play like that, it gives momentum to your team.”

Streaky sack men

Dwight Freeney tied Robert Mathis’ club record with a sack in an eighth straight game. A look at the longest streaks in NFL history:

[chart]
|No.|Player, team|Year(s)|
|10|Demarcus Ware, Dallas|2007-08|
|10|Simon Fletcher, Denver|1992-93|
|9|Bruce Smith, Buffalo|1986-87|
|9|Kevin Greene, Carolina|1997-98|
|8|Dwight Freeney, Colts|2008-09|
|8|Robert Mathis, Colts|2005|
|8|by several others||
[end chart]