07/09/2011 AT 7:20 PM ET
Rob Lowe, Jennifer Love Hewitt, Molly Sims, Joe Jonas, Zoe Saldana, Rosario Dawson and Billy Zane were on hand as the royal newlyweds arrived by helicopter and walked across the lawn to the Santa Barbara Polo & Racquet Club in Carpinteria.
“Catherine and I have had a busy few days so the prospect of being able to let loose this afternoon is wonderful for me,” William, 29, said in a brief speech.
As for whether he’ll return to Santa Barbara, he joked, “That depends on the result out there today – I’m not a good loser.”
Then as Catherine smiled and clapped, he went on to score four goals as his team won, 5-2.
Catherine, also 29, wore a silver and marble grey hand-painted chinoiserie silk dress by Jenny Packham to the event, where tickets went as high as $4,000 for a lunch by celebrity chef Giada De Laurentiis.
Reporting by MIA McNIECE, SIMON PERRY and DAHVI SHIRA