Both the actresses walked the red carpet for cosmetics giant L'Oreal Paris, but before they stepped out, they shared a warm moment together -- as seen in a photograph doing the rounds on social media. Sonam is seen planting a kiss on Mahira's forehead.
"Can't wait to hang out with you at Cannes," Sonam had earlier tweeted to Mahira, who has made her debut at the gala this time.
For her first red carpet look here, Sonam looked radiant and resplendent in a dreamy and delicate pastel-hued Ralph and Russo lehenga ensemble, with her hair loosely tied in a braid and accessorised with a detailed 'parandi'.
She wore simple earrings by Chopard, and the intricate henna design still adorned the hands of the actress, who married long-time beau Anand Ahuja just last week.
"Wearing a dress that feels like it's made of starlight," Sonam posted on Instagram.
She captioned another image: "Moonbeams and Mediterranean dreams", with a third photograph titled: "All the stars are out tonight."
Mahira, on the other hand, wore a black off-shoulder dress after the ensemble she was due to wear got stuck at the customs and didn't turn up in time.
"I'm nervous," she wrote before making her red carpet debut, but her confident demeanour was a head-turner at the gala, where she and Sonam walked one after another.
Mahira dedicated her representation at Cannes as an "ode to the people I have loved so much.... and have inspired me since I was a little girl. Starting from my Ama to Minaal and Rooha... down to all my girls back home in Pakistan".