They are two longtime Dodger villains, hated for two vastly different reasons.

As the last remaining position player from the Houston Astros’ trash-can-banging, and (in the eyes of most Dodgers fans) World Series-stealing 2017 championship team, Jose Altuve always receives a rude welcome from the fans at Chavez Ravine.

As one of the most productive visiting players in Dodger Stadium history, Christian Walker often shuts them up.

In the Houston Astros’ 18-1 Independence Day rout on Friday, both added another tortured chapter to the Dodgers’ history against the team. Altuve went three for three with a double, two home runs, two walks and five RBIs. Walker went four for five with one long ball and four RBIs.

On a day starting pitcher Ben Casparius once again struggled (giving up six runs in three innings), reliever Noah Davis gave up 10 runs in the sixth inning alone (the most the Dodgers had surrendered in one inning since 1999), and most of a sold-out crowd stuck around for every painful minute (waiting in somber silence for a postgame fireworks show), that was plenty to lift the surging Astros to most lopsided defeat the Dodgers have ever suffered at Dodger Stadium.

Six weeks ago, the retooled Astros were one game above .500 and 3 ½ games out of first place in the American League West; seemingly missing the other 2017 stars who have departed the franchise since their sign-stealing scandal came to light five years ago.

But now, they have won 27 of their last 37, own the second-best record in the AL, and are suddenly looking like unlikely title contenders; even after turning over almost the entirety of the roster from that infamous 2017 season.

“Certainly, there’s been some history with our organizations,” manager Dave Roberts said pregame when asked if any lingering feelings remained from the Astros’ sign-stealing scandal. “But if you look at it in reality, most of those guys are gone. So it certainly doesn’t have any bearing on this series this weekend.”

Instead, in a historically harrowing defeat on their home diamond, the Dodgers had bigger concerns to worry about Friday, with Altuve and Walker at the top of the list.

Altuve received his typical reception from the Dodgers faithful, serenaded with booming boos and loud chants of “cheater!” for each of his at-bats. However, he followed Isaac Paredes’ leadoff homer in the first with a double off the wall, then took Casparius deep for a two-run home run on a curveball in the third.

Those low-lights marked another frustrating night for Casparius, whom Roberts said will likely return to the bullpen moving forward after posting an 8.24 ERA in his last five outings as a starter and bulk-inning pitcher.

“Obviously, when you’re a starter, there’s more preparation that goes into the other side, as far as preparing for a starting pitcher versus a reliever, so I think there’s some [of] that,” Roberts said of Casparius’ struggles as a starter, compared to the 2.93 ERA he had as primarily a reliever to start the year. “But at the end of the day, he’s just got to execute better. There might have been 60 throws tonight, and probably only a handful executed where he wanted them to be. And that’s tough to do.”

Dodgers star Shohei Ohtani looks subdued while watching from the dugout as his team loses 18-1 to the Houston Astros at Dodger Stadium on Friday.

(Kevork Djansezian/Los Angeles Times)

Even when Casparius exited, however, Altuve wasn’t done, adding an exclamation point with a three-run homer in the Astros’ 10-run sixth — the most runs the Dodgers (56-33) had allowed in one inning since Fernando Tatis’ historic two grand slam inning in April 1999 with the St. Louis Cardinals.

Walker, meanwhile, was every bit as dangerous.

A 34-year-old slugger who dominated the Dodgers (and, most confoundingly, Clayton Kershaw in particular) during an eight-year career with the Arizona Diamondbacks, Walker was already emerging from an early-season slump in his first year with the Astros (53-35) entering this weekend’s series.

Then, back in the friendly confines of Dodger Stadium, he orchestrated a monster performance of his own from the five-spot of the Houston order.

In his first at-bat, Walker plated Altuve with a single the other way. Then, two batters after Altuve’s big fly in the third, Casparius left a fastball down the middle that Walker whacked for his 28th career home run against the Dodgers — and 20th at Dodger Stadium.

Only nine other players have hit that many home runs as visitors at the ballpark during their careers, a list that includes Hall of Famers Hank Aaron, Mike Schmidt and Willie Stargell, as well as Barry Bonds.

“It’s just one of those funny baseball things,” Walker told the Astros TV broadcast afterward. “No real explanation. Maybe good lights, I see the ball well? I honestly have no idea. It’s fun playing here.”

Walker also made a contribution in the sixth-inning onslaught.

After Davis gave up one run on two singles and two walks, the recently called-up right-hander plunked Walker with the bases loaded to force in another score, losing his grip on an 0-and-2 sweeper that left him visibly rattled on the mound.

Sensing Davis’ frustration, Roberts came to the bump for a motivational pep talk; eliciting memories of the mid-game hug he delivered to journeyman reliever Yohan Ramirez last season in Cincinnati.

This time, however, the mound visit had little effect. In the next at-bat, Davis threw a hanging sweeper that Victor Caratini belted for a grand slam. What was already a laugher became a full-fledged Fourth of July disaster.