Clayton Kershaw puts on a vint...

Ahead of the first matchup between Clayton Kershaw and Madison Bumgarner in almost five years, Dodgers manager Dave Roberts predicted the showdown would “bring out the best” in the two decorated left-handers.

He noted their career-long friendship and mutual respect; their competitive nature and equally intense internal drives.

“They always want to outdo one another,” Roberts said. “You're gonna see that come out tonight.”

The only problem?

Bumgarner no longer resides in Kershaw’s future Hall of Fame realm.

And in the Dodgers’ 10-1 win over the Arizona Diamondbacks on Saturday, the gulf between the two grew ever-more wide.

Kershaw, beginning his 16th major league season at age 35, dominated in a six-inning, one-run masterclass.

He fanned nine batters, many with a vintage curveball that awed a crowd of 48,886 at Dodger Stadium. He faced little stress, yielding just four hits and no walks en route to his 198th career win, leaving him two shy of another milestone.

And he had plenty of run support, bolstered by a three-home-run, eight-RBI outburst from Trayce Thompson — only the third such single-game performance from a Dodgers hitter in franchise history.

“You just try to protect the lead as best you can,” Kershaw said. “It’s a great way to get going into the season.”

Bumgarner, meanwhile, continued to look mired in his late-career slide.

Entering his fourth season in Arizona, where the 33-year-old posted a 4.98 earned-run average in his first three years, Bumgarner opened his 2023 campaign with a disastrous five-run first inning.

Mookie Betts led off with a double that might have been a home run if not for fan interference. Chris Taylor lifted a sacrifice fly to open the scoring. Then Thompson capped the outburst with a two-out grand slam — setting the tone for a career night at the plate that culminated with a curtain call in the bottom of the eighth inning.

“That doesn’t happen a lot, so that was pretty cool,” said Thompson, who had to be coaxed by a couple of teammates to make his modest bow after crushing his final home run halfway up the left-field pavilion.

“I always have belief and conviction in myself, so I know I can have nights like this,” Thompson added. “I’m just thankful that tonight was one of those nights.”

It all probably said less about Bumgarner, whose decline is hardly out of the ordinary for a high-mileage pitcher, and more about Kershaw, whose recent history of injuries remains the only discernible impediment he’s faced from father time.

“It amazes me in one sense, but it’s not surprising given who he is,” Roberts said. “He’s a testament to competing, [having] will, not taking a day for granted. That's something that is going to be part of his legacy going forward.”

It has also helped him transition into a new phase of his career, finding ways to sustain much of his trademark excellence — and provide a steadying presence that could be crucial to the Dodgers' starting rotation this year — even as he has moved past his three-time Cy Young Award-winning prime.