A cavalcade of Hollywood’s biggest stars welcomed Cirque du Soleil back to town Friday night, bringing added star power to the electrifying opening-night benefit performance of KOOZA at the Santa Monica Pier.

Proceeds from the performance and an extravagant afterparty — which totaled nearly half a million dollars — will support the ongoing work of local environmental group Heal the Bay and the ONE DROP Foundation, the clean-water nonprofit formed by Cirque founder Guy Laliberte.

The organizations greeted dozens of their celebrity supporters from the worlds of film, TV, music and sports, including such notables as event chair Julia Louis-Dreyfus and Brad Hall, Pierce and Keely Brosnan, Kelsey Grammer, Owen Wilson, Djimon Hounsou and Kimora Lee Simmons, Geena Davis, Neil Patrick Harris, Heather Graham, Heal the Bay board member Amy Smart, hockey Hall of Famer Luc Robitaille, and rockers Joe Walsh and Rick Rubin.

“We are so grateful to our friends at Cirque for creating such a magical night,” said Heal the Bay president Mark Gold. “Beyond raising critical funds to support the fight for clean water, the show and party energized all our supporters in a truly unique and captivating setting.”

The opening night performance of KOOZA marked a return to the origins of Cirque du Soleil — acrobatic performance and the art of clowning. The show mesmerized a crowd of 2,500 by highlighting the physical demands of human performance, presented in a colorful mélange that emphasizes bold slapstick humor and high-caliber acrobatic artistry.

To celebrate its 25th anniversary, Cirque du Soleil will present KOOZA under the blue and yellow Grand Chapiteau (big top) at the pier through Dec. 20.