SAN FRANCISCO -- Every now and then, it's not a bad idea to recall the immortal words of former Houston Rockets coach Rudy Tomjanovich: "Never underestimate the heart of a champion."
Rudy T. was referring to his back-to-back kings of the NBA in 1994 and '95, but his sentiments also apply to the three-time World Series champion Giants. Fans in San Francisco and its environs know never to underestimate these guys, even as their faith repeatedly is tested in odd-numbered years such as 2015.
With Tomlinson, filling in for Panik at second base, and Marlon Byrd, the new outfielder via Cincinnati, providing the muscle, the Giants stole the thunder from the Windy City's darlings after getting flattened in Tuesday night's series opener.
The Cubs were subdued in the space of 21 hours by Jake Peavy and the redoubtable Bumgarner, whose arms will have much to do with how the reigning champs fare in the season's final five weeks. The third starter in Bochy's latest rotation is Mike Leake, a veteran right-hander in the Peavy mold, acquired from the Reds.
The Giants have seven games left against the NL West-leading Dodgers, against whom they are 9-3. The first of these showdowns begin on Monday night, with a three-game series in Los Angeles, and wraps in the final days of September.
Bumgarner -- 16-6 overall and 5-0 with a 1.45 ERA in August -- can't face both Zack Greinke and Clayton Kershaw. Bochy needs other arms -- notably Peavy, Leake and Ryan Vogelsong -- to deliver quality innings.
"We're riding him pretty hard this month," Bochy said of Bumgarner, his big horse. "We were able to give him a break [only six innings] today. It was good to see our offense break out."
Byrd created a four-run cushion with his three-run homer off Dan Haren in the third. Tomlinson -- a 12th-round heist out of Texas Tech University in 2011 by scouting maven John Barr -- provided the icing in the eighth with his first career homer, a grand slam off James Russell.
A .346 hitter in 20 big league games with top-line speed, Tomlinson will add to the club's depth when All-Star Panik returns from lower back stiffness -- hopefully within two weeks.
Two weeks might be optimistic for the return of club heartbeat Pence from his left oblique strain, but Pagan is due back in center soon from right knee tendinitis.
Crawford's left oblique is considered a temporary issue. Matt Duffy, the breakout third baseman, impressed Bochy in going to the post after rolling an ankle on Wednesday night.
Asked about claiming the series from a Cubs club that had gone 21-4 starting on July 29, Bochy alluded to his team's well-established mental toughness.
"If anything," Bochy said, "it tells you these guys, they're pushing, going hard. We're going through a lot. It's obvious we have injuries to overcome. The first game, they got us pretty good. You've got to be resilient. We put together two good games against a good ballclub."
At 68-59, the Giants are 2 1/2 games behind the Dodgers in the division and 5 1/2 behind the Cubs for the second NL Wild Card, with the Pirates in the lead.
With 35 games remaining, Bochy said he believes his athletes "have time to find our way there." They do know the route.
From the "maniacal focus" ascribed by Bochy to Bumgarner, to the cool composure of Buster Posey and Crawford, the time-tested champions surrounding them can only help the newcomers respond to the pressures of late summer and early autumn.
"We have a lot of young players here," Bochy said. "These veterans do a really nice job of helping these guys. We're in a fight now, but people sometimes outside baseball don't know how big a moment this is for a Kelby Tomlinson.
"It's why you play the game. Let me tell you, you have to embrace it. I've been on the other end, where you're out of it.
"You want to be in the hunt and play every game like it's the seventh game of the World Series. They're all that important."
Lyle Spencer is a national reporter and columnist for MLB.com. Follow him on Twitter @LyleMSpencer. This story was not subject to the approval of Major League Baseball or its clubs.