SAN FRANCISCO — All week long, Frank Gore had a quick, supportive message to ease Jim Harbaugh's mind whenever he sensed his coach was unnerved: "Coach, we got this."
"He came up to me probably a half dozen times," Harbaugh said. "I believed him. I trusted him."
Gore made good on his mantra, all right. He's headed to the playoffs for the first time, and as San Francisco's career rushing leader to boot.
The two-time Pro Bowler and his 49ers trounced the beat-up St. Louis Rams 26-0 on Sunday to become the NFL's second team to secure a playoff berth behind unbeaten defending Super Bowl champion Green Bay.
Harbaugh's team, in command since Week 1, wrapped up that long-awaited NFC West title with four games to go. This has been quite the resurgence for a once-proud franchise determined to return to the glory days of Jerry Rice and Joe Montana, Steve Young and Roger Craig.
Gore waved a giant 49ers flag all the way back to the celebratory locker room.
He and Vernon Davis, Alex Smith and Patrick Willis, they're all taking their trusted leader — Harbaugh — to the postseason next month as playoff first-timers.
The 49ers are division champs and back in the playoffs for the first time since 2002.
"It's sweet to clinch it, especially at home," said Smith, the 2005 No. 1 overall pick who has been beaten down time and time again during a rocky seven years in the Bay Area only to prevail under Harbaugh's guidance. "It's the first step. We talked about it all week — win the division. Obviously it hasn't been done around here in almost a decade. We've talked about it since I've been here, and it's no different this year."
Harbaugh delivered exactly what the 49ers hired him for back in January: immediate success, a major transformation in a matter of months. So much for the lockout slowing him down.
Left tackle Joe Staley delivered the Gatorade dousing on Harbaugh's head in the closing moments — sneaking up on the coach at the 2-minute warning. Or so he thought. Harbaugh, a 15-year NFL quarterback himself in his day, dodged out of the way to avoid being fully soaked.
"This step, this game today is for all those strong and mighty men who have been carrying the flag for this many years," Harbaugh said. "Each year that they've been here, thinking that was going to be the year, the year we go to the playoffs ... and there's disappointment when you don't make that."
Gore helped run San Francisco (10-2) right into the postseason, passing late Hall of Famer Joe Perry and finishing with 73 yards to become the franchise leader in yards rushing at 7,417.
Smith threw second-half touchdowns of 52 and 56 yards to Michael Crabtree and Kyle Williams, respectively, and David Akers kicked four field goals to help Harbaugh join George Seifert (1989) and Steve Mariucci (1997) as the only rookie coaches in franchise history to win the division.
The only downer came when Willis left the game in the first half with a right hamstring injury that Harbaugh afterward said he didn't consider serious.
Rams quarterback A.J. Feeley struggled in place of injured starter Sam Bradford for the reeling Rams (2-10), who watched several more key players go down.
Even Feeley needed X-rays afterward on his right thumb.
"It's kind of the same story we've had all year. We just can't seem to put anything together," he said. "It's like a clock where everybody's got to be in sync. When that doesn't happen you put yourself in a tough situation."
The 49ers bounced back from a discouraging 16-6 loss at Baltimore on Thanksgiving night against the Ravens and Harbaugh's big brother, John, with another methodical victory. Smith was sacked nine times in that game and four more Sunday.
Despite further problems converting in the red zone early, San Francisco shut out an opponent for the first time since a 35-0 home win at Candlestick Park on Oct. 4, 2009. That was also the Rams' last shutout.
The Inners also avenged a late-season loss from 2010 that was still plenty fresh. They had won five straight before losing at St. Louis in the second-to-last week. It was after that game when coach Mike Singletary was fired. That led to the high-profile hiring of Harbaugh in January. And the 49ers' transformation began in earnest.
San Francisco's impressive season might help shed that "NFC Worst" stigma from the West.
"It's not a Hollywood team," Harbaugh said. "It's a blue-collar team."
Smith, who didn't start that last game against the Rams, completed 17 of 23 passes for 274 yards with no interceptions to finish with a career-high 142.3 quarterback rating. He gave way to rookie backup Colin Kaepernick midway through the fourth.
Gore ran for 2 yards early in the second quarter to give him 7,345 career yards rushing, moving him past Perry (7,344) for most in franchise history.
The 28-year-old Gore, a two-time Pro Bowl selection in his seventh NFL season, has said it was a goal for this season to become the career rushing leader — though getting to the playoffs for the first time has always been the top priority.
"There've been some tough years here," Gore said. "To get an opportunity to get to the postseason and to get it early, that's a blessing."
Gore and his teammates are wearing No. 34 helmet decals this season in honor of Perry, the first player with back-to-back 1,000-yard rushing seasons and nicknamed "The Jet" for his sensational speed. He died in April at age 84.
Willis watched the second half on the sideline in a sweat suit.
The four-time Pro Bowler landed awkwardly after missing a tackle on fullback Brit Miller, who grabbed an 18-yard completion from Feeley with 4:28 left in the first quarter. Willis' body twisted as he fell to the ground and he stayed down for a short time as trainers ran out to check on him, then helped him limp off the field.
Akers kicked field goals of 36 and 19 yards then booted a 28-yarder 1:41 before halftime for his 31st of the year, topping Jeff Wilkins' single-season franchise mark of 30 set in 1996.
The 49ers certainly hope there's more to come.
"We want to make it to the championship. It's something we've been wanting for a long time," Davis said. "This is the reason why I'm here. It means a lot to me."
Notes: Rams LG Jacob Bell (right knee) left and didn't return. ... The Niners are unbeaten in their last 10 home games vs. NFC West. ... Rookie Aldon Smith also had two sacks. ... Rams DE Chris Long has a sack in six straight games.