Thirteen seconds once won Vicki Lawrence $300.

That was her guess for how long it would take for Harvey Korman to lose his composure.

Fans of “The Carol Burnett Show” already know the routine. Korman would be cast in a skit with Tim Conway, whose antics push Korman out of character and into laughter in front of a live studio audience.

Conway never failed to achieve, so the cast began keeping a cash pool on Korman in the green room before every show.

“We’d all take a guess as to how long it would take Harvey to start laughing,” Lawrence says, speaking from her Los Angeles home. “I won $300 one time for guessing 13 seconds.”

She laughs. It’s a good memory, a behind-the-scenes story to tonight’s “Carol Burnett’s Favorite Sketches” airing at 9 on WLPB, Channel 27 (cable Channel 12).

Burnett has chosen several popular sketches from her comedy-variety series that aired Saturdays from 1967 to 1978, including “As the Stomach Turns: Close Encounters,” “The Dentist,” “Went With the Wind,” “Nora Desmond: The Commercial,” “The Oldest Man: Galley Slaves,” “The Family—Sorry!” “Tudball and Wiggins” and “As the Stomach Turns: Mother Marcus.”

And though Lawrence won’t be beside Burnett hosting the program, she will appear in the sketches, most of which also are favorites.

She remembers playing Burnett’s daughter in the “As the Stomach Turns” soap opera spoof, always showing up with a new baby.

“It was never the same baby,” Lawrence says. “It was supposed to be illegitimate.”

And she thought she did a pretty good job playing Prissy in “Went With the Wind,” a spoof of the 1936 movie classic, “Gone With the Wind.”

“I think I did well on that one,” she says. “And, you know, there’s an interesting story behind that sketch. It’s the sketch everyone remembers, the one where Scarlett comes down the stairs wearing the curtain rod.”

The behind-the-scenes story here is found in the sketch’s origins. “Carol Burnett” was a CBS show, but the writers who offered it up were from NBC.

“But they were writers over there — these two guys were ushers at NBC,” Lawrence says. “They came together and wrote it, and we loved it. It was a hit, and afterward they were hired as writers for our show.”

It was a different time in Hollywood, when the title of Miss Fireball in Inglewood, California, could lead to a 12-year stint on one of television’s most popular series. That’s how it happened for a 16-year-old Lawrence.

Her entry into the contest, named for the annual Inglewood firemen’s ball, prompted a local newspaper reporter to write about her resemblance to a young Carol Burnett. Lawrence’s mom knew Burnett read fan mail and urged her daughter to send the article to the star.

Lawrence did, and Burnett not only attended the contest but was called for the crowning when Lawrence was declared the winner.

Meanwhile, Burnett was looking for an actress to play her younger sister in the “Carole and Chrissy” sketches in her new show. Lawrence was 17 when she joined the legendary series, and would end it playing Burnett’s mother.

“I went from little sister to Mama, so how did that happen?” Lawrence asks, again laughing. “You know, before Mama, I didn’t have many recurring characters on the show.”

But Mama has been good to Lawrence, resulting in the spinoff sitcom, “Mama’s Family,” after “The Carol Burnett Show” went off the air, along with a continuous stage show, “Vicki Lawrence & Mama: A Two-Woman Show,” which traveled to Baton Rouge in 2014.

Mama was introduced as Eunice Higgins’ mother, Thelma Harper, in the Burnett show’s “The Family” sketches. Burnett played Eunice and Korman played her husband, Ed. The family, of course, was dysfunctional, which accounted for much of the comedy.

Mama, Eunice and Ed also were Southern.

“I drew a lot of Mama’s characteristics from my own mother, who was dysfunctional,” Lawrence says. “I also drew a lot from my ex-mother-in-law, who was Southern.”

And speaking of exes, it was Lawrence’s ex-husband, Bobby Russell, who penned her only pop hit, “The Night the Lights Went Out in Georgia.” Ironically, Russell didn’t write it for her and was afraid to shop it around after finishing it for fear it would offend Southern listeners.

Yet the song told a story, and something Southerners love.

“I love songs that tell stories, too,” Lawrence says. “When I was a teenager, our story song was, ‘Ode to Billy Joe,’ and it was set in the South. We had vinyl albums, and there was no internet, so you couldn’t automatically look up the lyrics. So we’d keep dropping the needle back to the same spot on the record so we could get all the lyrics down.”

Another laugh.

“My mother would finally yell at us, ‘Would you stop playing that song — you’re driving me crazy,’” Lawrence says.

“The Night the Lights Went Out in Georgia” probably was as big a hit in the state in which it was set as everywhere else in the United States. A friend suggested that Lawrence’s then-husband give it to her to record. The single went gold in 1973 but she ended up being a one-hit wonder.

“That was a doomed end to a doomed marriage,” Lawrence says.

She and Russell divorced in 1974 and she married Hollywood makeup artist Al Schultz later that year. The couple had two children and live in Los Angeles.