SAN FRANCISCO -- It wasn’t too long ago that 2021 looked like the potential end of an era for the Giants.

Two years prior, Buster Posey, Brandon Crawford and Brandon Belt -- the three remaining members of the Giants’ championship core -- were coming off the worst seasons of their careers and appeared to be entering a period of interminable decline. With the trio then eligible for free agency at the end of '21, there was a sense their run together would soon be coming to an end.

Then came the most unexpected renaissance.

More than a decade into their careers, Posey, Crawford and Belt managed to beat the odds and reach new heights, emerging as the veteran pillars of a Giants team that stunned the baseball world by transforming into a 107-win behemoth and snatching the National League West crown from the vaunted Dodgers.

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Posey, 34, hit .304 with an .889 OPS and 18 home runs over 113 games, his best numbers since he won the National League MVP Award in 2012. Crawford set career highs in virtually every offensive category, batting .298 with an .895 OPS and 24 homers over 138 games, while continuing to provide Gold Glove-caliber defense as a 34-year-old shortstop. Before sustaining a left thumb fracture in late September, the 33-year-old Belt was also in the midst of a career season, hitting .274 with a .975 OPS and a team-high 29 homers over just 97 games.

“Those guys, it’s been incredible,” right-hander Logan Webb said. “But at the same time, is it something we didn’t see coming? Those guys have done it for a long time, and they’ve won. I feel like those guys just proved that they’re winners, and they’re very, very, very good baseball players.”

It felt fitting that Posey, the Giants’ longest-tenured player, delivered what president of baseball operations Farhan Zaidi called “the biggest moment of the season” in Sunday afternoon’s 11-4 rout of the Padres, which clinched the club’s first division title since 2012.

In the third inning, Posey stepped up to the plate with the bases loaded and came through with a two-run single that gave the Giants a lead they would never relinquish. He celebrated the moment with an emphatic fist pump, a rare show of emotion from San Francisco’s normally stoic catcher.

“That was just awesome to see,” Zaidi said. “Somebody like that, that has that low-key demeanor, even though he’s seen a lot and been so successful. You see that, and you know that these guys have been waiting a while to get back to a moment like this. It’s got to be really validating for them. I feel really happy for them.”

Posey’s last playoff push with the Giants came in 2016, as he sat out last year’s pandemic-shortened campaign after he and his wife, Kristen, adopted twin baby girls who were born prematurely. The hiatus may have benefited Posey in the long run, though, giving his body more time to fully recover from a right hip injury that required major surgery and sapped his power, resulting in a career-worst .688 OPS in 2019.

Posey worked with Giants hitting coaches Donnie Ecker, Justin Viele and Dustin Lind to make swing changes that helped spark his revitalization at the plate, but manager Gabe Kapler also remained disciplined with the veteran catcher’s usage throughout the regular season, making sure Posey received enough rest to remain fresh and productive down the stretch.

“To have not played last year, and then come back and have the year he had was a big reason why we’re in this position,” Crawford said. “As a teammate, as a friend, it’s nice to see.”

“I think what he’s done this year is pretty special,” Webb added. “It’s not only on the field, it’s in the clubhouse, too. The calm presence he gives, I think that helps out a lot of guys. It’s not just young guys like me, but I think the older guys that need it as well. He’s a special person.”

Crawford’s resurgence was perhaps a bigger surprise considering he hit only .228 with a .654 OPS and 11 homers over 147 games in 2019. To his credit, Crawford also showed a willingness to make changes, working with the Giants’ hitting coaches to clean up his bat path and tweak his setup to put him in a better position to do damage at the plate. His steady production, coupled with his stabilizing presence on the infield, turned him into San Francisco’s leading NL MVP candidate this year.

“I think Craw, his ability to be in the lineup every day as a 34-year-old -- take the offensive, defensive metric values aside -- just the stability that he gives our team, going out there almost every single day, is probably as important as anything,” Posey said. “He should definitely be in consideration.”

The Giants rewarded Crawford for his resurgent season by signing him to a two-year, $32 million contract extension in August, while Posey is likely to have his $22 million team option for 2022 picked up if he doesn't negotiate a new deal over the offseason. Belt’s future is a little more uncertain, though he did emerge as one of the top hitters in the league before going down. It’s unclear if he’ll be able to return for the postseason, but he has plenty of fans in the Giants’ front office, so it’s not hard to envision him staying in San Francisco beyond 2021 as well.

“I actually think he can get better,” Kapler recently said of Belt. “I think he’s as well-rounded of a hitter as there is out there. I think the power is getting better. I think his bat is moving through the zone better than it has in years' past. I think he’s more confident than he ever has been. He can do everything at the plate, and he’s fearless seeing the ball with two strikes. Super smart hitter. I just think the world of him as a baseball player. Not only do I think he can keep this up, but I think he can get better and do it for a long time.”

The Giants have undergone significant changes over the past few years, but their foundation continues to endure, a testament to the rare longevity Posey, Crawford and Belt have enjoyed together. Against all odds, the battle-tested veterans are once again leading the Giants into October, and they’re hoping this latest run won’t be their last.

“I'm proud of all of us. Being able to bounce back from a few tough seasons, and come back out here and perform the way we have,” Crawford said in September. “And I think a lot of that has to do with the coaching staff, whether it's giving us days off to keep us healthy, or swing changes and approach changes that we've made over the last couple of years. I'm happy for all of us. Hopefully, we can keep it going and win some more games.”