joined for her fourth Annual Joyful Heart Walk in the Hamptons two days ago.

On Thursday, the Blue Lagoon actress, 58, took to Instagram to share a photo of herself at the fundraising event with the Law & Order star — who is also the founder and president of the charity.

The two best friends were also joined by their pal, Living Color alumna Ali Wentworth, 58.

In her caption, Shields — who enjoyed a relaxing spa day with

 Rowan, 20, over a week ago — gushed over Hargitay and expressed admiration for her philanthropy.

'4th Annual Joyful Heart Walk,' she wrote alongside a red heart emoji. 'So proud of [Mariska Hargitay] and all of the important work [The Joyful Heart Foundation] does!'

Trio of best friends: Brooke Shields joined Mariska Hargitay for her fourth Annual Joyful Heart Walk in the Hamptons two days ago.

 The two best friends were also joined by their pal, Living Color alumna Ali Wentworth, 58

For the walkathon, the former child model dressed comfortably in an all-black ensemble.

To stay cool in the heat, she sported a loose-fitting tank top and a pair of figure-hugging leggings.

She also represented the foundation by donning a black trucker hat with the organization's name emblazoned across the front.

Underneath the cap, the Pretty Baby star left her brunette tresses down in a casual and straight hairstyle.

Then, she shielded her eyes from the sun with a pair of dark shades with an aviator-style frame.

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