This “Westworld” bit player has been upgraded to a series regular.

Guest star Louis Herthum’s turn as Evan Rachel Wood’s android “father” on the HBO sci-fi/Western hit was so impressive that he’s now playing an even more pivotal role in season two, coming in late 2017 or early 2018.

This is the breakout that the 60-year-old actor, who’s also appeared in “Murder, She Wrote,” “True Blood” and “Longmire,” has been working toward for the past 35 years.

“Overjoyed, honored, grateful and or so fortunate to be a part of this amazing show!” he tweeted.

Herthum has even landed a role on the big screen opposite Johnny Depp and Forest Whitaker in the upcoming “LAbryinth,” about the investigation into the Notorious B.I.G. and Tupac Shakur murders.

Scene-stealing parts can be career-makers when actors play them right. Here’s some other breakout roles that catapulted supporting actors into superstars.

Suzanne “Crazy Eyes” Warren from “Orange is the New Black”

The Litchfield inmate looking for love in all the wrong places was initially sentenced to just a couple of episodes in the first season. But her performance was so powerful that Crazy Eyes has become one of the most beloved characters on the Netflix series, and actress Uzo Aduba has won two Emmys for the role.

Elmo from “Sesame Street”

The Muppets created a monster with this furry little fellow that first visited the Street in the 70s, but became a marketing juggernaut in the 1990s. Kids went crazy for the sweet monster with the falsetto voice, which led to his own “Elmo’s World,” segment. And who could forget the “Tickle Me Elmo” toy shortages in the late 90s that sent parents to the brink of madness each holiday shopping season? Elmo is still doing A-OK.

Barb from “Stranger Things”

She had just a few scattered minutes of screentime before getting killed three episodes in. But the ginger misfit in the mom jeans struck a chord with viewers, especially since her disappearance was barely acknowledged onscreen. Her face launched trending hashtags #WhatAboutBarb and #JusticeForBarb – and even an Instagram post from John Stamos himself captioned “#ImWithBarb.” Now actress Shannon Purser plays a recurring character on the CW’s “Riverdale,” and she’ll join NBC’s pilot “Drama High” in a role written just for her.

#ImWithBarb

A post shared by John Stamos (@johnstamos) on

Steve Urkel on “Family Matters”

Did he do that? Jaleel White’s nasal nerd with the big glasses and suspenders was supposed to be a one-off character on the 1990s family sitcom, but the audience found his clumsiness and his unrequited love for Laura Winslow hilarious. He not only became a series regular – Urkel is now synonymous with the entire show.

Arthur “Fonzie” Fonzarelli from “Happy Days”

Aaaeeeyyyy – he’s the king of all breakout stars. Give two thumbs up to Henry Winkler’s pompadoured biker with the black leather jacket, who was supposed to be just a fringe character but ended up replacing Richie Cunningham’s best friend. Soon he rode up to second-billing on the cast, and network execs even kicked around renaming the show “Fonzie’s Happy Days.”