For Jennie Garth, Shannen Doherty was more than just the Brenda to her Kelly.

The actress paid tribute to her former Beverly Hills, 90210 costar July 14, hours after it was announced that she died at age 53 after a lengthy cancer battle, and took the opportunity to debunk longtime negative rumors about their relationship.

"I am still processing my tremendous grief over the loss of my long time friend Shannen," Jennie wrote on Instagram, alongside two pics of the pair on the 90210 set. "the woman I have often described as one of the strongest people I have ever known."

The actress and Shannen were officially photographed together in the years following their time on 90210. The two also appeared together in the 90210 sequel series in 2009 and costarred in the 2019 BH90210 mockumentary.

"Our connection was real and honest," Jennie said. "We were so often pitted against each other but none of that reflected the truth of our real relationship which was one built on mutual respect and admiration."

Jennie called Shannen, who was first diagnosed with breast cancer in 2015, "courageous, passionate, determined and very loving and generous."

"I will miss her and will always honor her deeply in my heart and in my memories. My heart breaks for her family and Bowie and all the people who loved her," the 52-year-old wrote, referring to her friend's beloved German Shepherd.

Shannen, who left 90210 in 1994 after the first four seasons, is the third member of the original cast to pass away. Joe E. Tata, who played Peach Pit owner Nat, died at 85 in 2022. Three years prior, Luke Perry suffered a fatal stroke in 2019 at age 52.

He played Dylan McKay, who was involved in a love triangle with Shannen's Brenda Walsh and Jennie's Kelly Taylor, who were besties but became rivals after the late star's character found out about their affair, an iconic '90s pop culture moment rooted in the memories of scores of fans of the show, which aired for 10 seasons.

Jennie, who starred in all of them, has spoken before about her real-life relationship with Shannen.

In her 2014 memoir Deep Thoughts From a Hollywood Blonde, the actress called her costar one of her "dearest, closest friends," who she initially found "intimidating" and "intense."

Jennie also wrote about a time the two nearly came to blows after Shannen tried to playfully get her to break character while filming by pulling up her costar's skirt. Jennie said Luke and Jason Priestley, who played Brenda's twin brother Brandon, had to pull them apart.

"I'm pretty sure I got in her face, but we're just both strong Aries women," Jennie later recalled on Watch What Happens Live in 2019. "We don't back down—no matter what."

Shannen herself also recalled the incident earlier this year. "She was calling it 'Pants-Down Day,'" she said about Jenner on the March 3 episode of her podcast, "where she would pull the pants on some of the crew members in a funny way." 

After several of them got annoyed by it, the actress turned the tables on her costar. "I said, 'Skirt-Up Day,'" Shannen recalled to her guest, fellow 90210 alum Brian Austin Green. "She always wore the men's Calvin Klein boxer shorts under her clothes, so I didn't think it was that big of a deal."

Brian noted, "It was a huge moment for everyone."

Both the actor and Jennie are among several 90210 alumni who paid tribute to Shannen on social media following her death. Read more homages to the late actress...

“Shocked and saddened to hear about the passing of my friend Shannen,” the actor, who played Brandon Walsh, the twin brother of the actress' character Brenda Walsh on Beverly Hills, 90210, expressed on Instagram. “She was a force of nature and I will miss her. Sending love and light to her family in this dark time.”

"Shan. My sister," the Beverly Hills, 90210 alum wrote on his Instagram Stories. "You loved me through everything. You were a big part of my understanding of love. I'll miss you more than I know how to process right now. Thank you for the gift of you."

“So young – so sad,” the Beverly Hills, 90210 and former SAG-AFTRA president wrote on Instagram. “May you RIP Shannon. I know Luke is there with open arms to love you."

The actress-turned-therapist, who played Cindy Walsh, the mother of Shannen and Jason Priestley's twin characters Brenda and Brandon, wrote on Instagram she was "shocked and saddened" by news of her onscreen daughter's death.

"What a journey she has been on!" she wrote. "Gone too soon. Throughout, she stayed true to herself and gave us an example of courage and perseverance in facing her own death. May she rest in peace."

"It's no secret that Shannen and I had a complicated relationship, but at its core was someone I deeply respected and was in awe of," she said of her Charmed costar in a statement to Entertainment Weekly. "She was a talented actress, beloved by many, and the world is less without her. My condolences to all who loved her."

"A true lion heart," the actress, who replaced Shannen on Charmed in 2001 after she left the series, wrote in a comment on the late star's final Instagram post. "What a warrior. Your daddy is holding his best girl now."

She continued, "Love to your mama, your dog and all who love you fiercely. Love to Holly [Marie Combs]. Love to all of your legions of fans that I know you loved right back. If there was anyone who looked squarely at death and said no thanks, it was you dear Shannen. My head bows to you brave one. All love forever."

"You showed me what strength is," the actor, who played Leo Wyatt on Charmed, shared on Instagram. "You taught me to be fearless and live with purpose. To know your value and stick to your determination."

"Forever loved!" he added. "Truly heartbroken."

"I am absolutely heartbroken over the passing of Shannen Doherty." the Newsroom alum wrote on her Instagram Stories July 14. "When I was first diagnosed with breast cancer I remembered how she bravely let the world into her journey and reached out to her. We became instant friends- which I honestly couldn’t comprehend at times because watching her on 90210 was everything to me when I was 10."

"We bonded through a shared battle and a desire to help other women," she continued. "Looking back on the last text she sent me just a couple months ago, she asked how I was doing and if she could do anything for me… true to form, Shannen was offering her support even though she was in the final stage of fighting this horrific disease."

Olivia concluded her statement with a heartfelt message to her late friend. "Cancer is really f--king scary and Shannen faced it with such dignity, strength and grace," she expressed. "I’m sending all of my love to her mother who was her best friend, hero and champion every step of the way. Fly so high, my friend."

"Thank you for being here," the actress, who is battling multiple sclerosis, commented on Shannen's final Instagram post. "Thank you for showing us how to keep going. Rebel heart."

"Love you," the actress wrote in a comment on Shannen's last Instagram post. "Fly high lovely kind sweetheart woman. This hits hard. Your heart,courage and kindness will be so missed."

"Your bravery and ability to share your Cancer journey left something 'in' people," the Oscar winner wrote on Instagram. "Rest well. God bless your loved ones."

The actor, who guest starred on Beverly Hills, 90210 as Rick, who Shannen's character Brenda dated briefly after meeting him in Paris, wrote on X, "RIP Shannen," adding a crying emoji.

The Wicked star wrote in an Instagram comment, "Fly with the angels sweet precious soul!"

"My heart is broken," he wrote on Twitter. "It was a pleasure to meet Shannen Doherty while filming our movie Fortess a little over 2 years ago! She was full of warm energy and positive vibes. So young. So talented. May she rest well."

"RIP Shannen Doherty," he wrote on X, formerly Twitter. "I met her during the Full House days. She was lovely and had a beautiful smile. Today, I’ll also think about the women in my life who all succumbed to cancer - my mom, my sister, Sharon and my niece, Shannon, who all were so strong and so beautiful."

Alongside an article reporting Shannen's passing, the journalist wrote on Instagram, "I'm so sad to hear this news..."

"Such sad news," the Community actress wrote on Twitter. "I was hoping she would beat the disease again."

For the latest breaking news updates, click here to download the E! News App