OAKLAND -- Madison Bumgarner strolled into Bruce Bochy’s office Sunday morning and informed his longtime manager that he was on the verge of a notable milestone. Up until that point, Bochy had no idea that the Bay Bridge Series finale would mark his 4,000th game as a manager. 

 “You know, you’re really old,” Bumgarner said. 

 The same thought dominated Bochy’s mind as he mulled over what it meant to become the eighth manager to reach the threshold. The other seven are in the Hall of Fame, and Bochy is a virtual lock to join them.

• Box score

 “I’m getting up there,” Bochy said. “That’s really what it is. It’s longevity. I’m fortunate that I’ve had some people support me and keep me around. That’s a lot of games, though. I never thought about it. I look back and it just kind of flew by, to be honest. It’s flying by now.” 

 The Giants honored Bochy with a cake shaped like the number 4,000 before the game, and the day became even sweeter after his club rallied to beat the A’s, 5-4, at the Coliseum to clinch The Bridge trophy.

San Francisco secured its second consecutive win over its cross-Bay rival behind another milestone afternoon from third baseman Evan Longoria, who crushed a game-tying home run in the third inning for his 1,000th RBI before adding a go-ahead two-run single in the seventh.

“He’s doing things that he’s done his whole career,” Bochy said. “It kind of got lost in the shuffle here a little bit how big he was. Both games [in this series], we don’t win without him.”  

The Giants entered the seventh trailing by one, but they staged a comeback against A’s reliever Jake Diekman. Brandon Crawford reached on an error by Matt Olson, Donovan Solano walked and Mike Yastrzemski reached on a hit by pitch to load the bases with no outs.

A’s manager Bob Melvin summoned Blake Treinen to face Buster Posey, who fouled off seven pitches before swinging through a cutter to end an 11-pitch at-bat. That brought up Longoria, who poked a first-pitch sinker through to left field for a two-run single that gave the Giants a 5-4 lead.

Longoria was one of the Giants’ hottest hitters during their torrid stretch in July, though he encountered a setback after landing on the injured list with plantar fasciitis in his left foot. The 33-year-old veteran missed 19 games, but he’s managed to pick up where he left off, going 23-for-68 (.338) with two doubles, four homers and 17 RBIs since returning from the IL on Aug. 4. 

“Not too many people on this coast know how good of a player Evan Longoria is,” catcher Stephen Vogt said. “I was fortunate enough to be his teammate before here [with the Rays], so we all know how good he is. When he gets going, there’s nobody hotter in baseball. I love the way he’s looking right now. His tempo is really good. He’s not missing pitches.” 

Longoria said that he was aware that he was closing in on 1,000 RBIs, as he had discussed the milestone with mental skills coach Derin McMains and had set it as one of his goals for the season. He reached it by hammering his 17th home run of the year, a solo shot off of A’s left-hander Brett Anderson in the third. With five weeks left in the regular season, Longoria has now eclipsed his home run total from last year, when he led the Giants with 16.

“It’s a proud moment,” Longoria said. “It’s not something I ever thought I would do. Until this year, it’s not something that I’ve even thought about. It’s nice to get there.”  

The Giants’ two-game sweep of the A’s allowed them to climb back to .500 at 65-65 and stay within four games of the second National League Wild Card spot with 32 games left to play. They remain long shots to make the postseason -- FanGraphs pegs their playoff odds at 1.4 percent --  but they believe that they can continue to play meaningful baseball deep into September and make Bochy’s final season a special one.

“We’ve put ourselves in a spot to have a fun last month,” Longoria said. “At least it’s interesting, and at least it still feels like we’re playing for something. I think everybody believes that we can still kind of do something special if we do what we’re capable of doing.”