POLO CHALLENGE
It’s time again for the Mercedes-Benz Polo Challenge! Catch the matches that run for six consecutive Saturdays, through August 20, and watch the sport’s greatest athletes compete for one of Polo’s most coveted prizes, while schmoozing under the tent. Proceeds from the Challenge benefit the South Fork Breast Health Coalition. 4 p.m. Bridgehampton Polo Club, Bridgehampton. For more info, call: 212-420-9420, x22.

DINING BY DESIGN
The annual Elle Décor “Dining by Design” gala will benefit the Design Industries Foundation Fighting AIDS. More than 50 designers will come together to stretch their collective, creative muscles designing inventive tabletops! 7:30 p.m. East Hampton Studios, East Hampton. Call: 212-727-3100.

BAY STREET THEATRE GALA
Enjoy dinner and performances from the Broadway show “Forever Tango” at Bay Street Theatre’s Summer Gala benefit Bash. Don’t miss the live “Fantasy” auction, which will include a dazzling Harry Winston diamond bracelet watch valued at $44,300! 6:30 p.m. Siena Spirituality Center at Villa Maria, Water Mill. Call: 631-725-0818.

HAMPTONS HAPPENING
Support the Samuel Waxman Cancer Research Foundation as it hosts its annual benefit, “Hamptons Happening.” Sample delectable dishes by top-notch restaurants including: Il Cantinori, Sette, The Four Seasons, and Amuse. 6 p.m. Private residence, Southampton. Call: 212-241-1760.

AFRICAN ODYSSEY
Take a walk on the wild side as the gardens of LongHouse Reserve, whose mission is to exemplify living with art, are transformed into an exotic safari fantasy. 6 p.m. LongHouse Reserve, East Hampton. Call: 631-329-3568.


VH1 SAVE THE MUSIC
Jerry Della Femina and Judy Licht will, once again, open their beautiful East Hampton beachfront home for the 18th annual Garden Gala benefiting Body Positive. Betsey Johnson will receive the James Revson Award. 5 p.m. Private Residence, East Hampton. Call: 212-566-7333, x24.


BLUE MOON BALL
Catch the Blue Moon Ball BBQ, benefiting EECO Farm. This foodie fantasy will include a performance of the Off-Broadway hit Cookin’ at the home of James and Ellen Marcus. Honorary chairs include: Christie Brinkley and Peter Cook, and B. Smith and Dan Gasby. 7 p.m. Private residence, East Hampton. Call Linda Shapiro: 631-329-5480.

SUPER SATURDAY
Shop till you drop at “Super Saturday 8,” the annual shopping bonanza benefiting The Ovarian Cancer Research Fund. Hosts of this luxe designer garage sale: Donna Karan and InStyle’s Charla Lawhon. Committee includes: Kyle MacLachlan and Desiree Gruber, Christy Turlington, Amy Sacco, Serena Altschul, Peter Boyle, Christie Brinkley and Peter Cook, Aerin Lauder, Gillian Hearst-Shaw. 1 p.m. (with exclusive preview shopping at noon). Nova’s Ark Project, Water Mill. Call: 212-268-1002.

WATERMILL CENTER BENEFIT
The Watermill Center will be transformed into a South American paradise for Robert Wilson’s Brazil-themed Annual Water Mill benefit, which will support the completion of the art center. Participating artists include: Kiki Smith, Sol Lewitt, Chuck Close, and Ross Bleckner. 6 p.m. Watermill Center, Water Mill. Contact: 212-253-7484, x10.

ART FOR LIFE
Kimora Lee and Russell Simmons will host “Art for Life,” which benefits the Rush Philanthropic Arts Foundation, at their scenic East Hampton spread. The event will honor M.A.C.’s John Demsey and Pratt Institute’s Tom Schutte. 6 p.m. Private residence, East Hampton. Call: 212-997-3034.

VROOM! VROOM!
Get your engines ready for the 4th Annual Speeding to a Cure summer party benefiting the Juvenile Diabetes Research Foundation. Hosted by Ron and Denise DelGaudio, this event will showcase over 75 Ferrari and Maserati cars, as guests enjoy a scrumptious buffet! 9 a.m. Saracen’s Restaurant, Wainscott. Call: 212-478-4317.


SOUTHAMPTON HOSPITAL BASH
The safari-themed 47th Annual Summer Party benefit will support the Southampton Hospital’s Department of Emergency Medicine. Chairs include: Vera Wang, Sheila O’Malley Fuchs, and Cindy Willis. Emcee: Kelly Ripa. 7 p.m. Wickapogue Road, Southampton. Call: 631-726-8700.


RIVERKEEPER BENEFIT
Anne Hearst will host the Hudson Riverkeeper/Peconic Baykeeper benefit at her home in Water Mill, which raises funds to protect and preserve the Hudson River, the Peconic Bay, and Long Island’s South Shore. Robert F. Kennedy Jr. will be the featured speaker. Junior committee chair: Amanda Hearst. 6:30 p.m. Private residence, Water Mill. Call Linda Shapiro: 631-329-5480.


MEOW MEOW BOW WOW
Join a few of our four-legged friends at Animal Rescue Fund (ARF) of the Hamptons’ annual summer dance. Ellen and Chuck Scarborough will host the furry festivities at their beautiful Southampton home, which will include an auction conducted by George McNeely of Christie’s. 7 p.m. Private residence, Southampton. Call: 631-537-0400, x208.


THE HORSES ARE COMING!
It’s time once again for the 30th Annual Hampton Classic Horse Show benefiting Southampton Hospital. The event runs through Sept. 4 (ending with its grand finale, the celeb-packed Grand Prix). 8 a.m., daily. Hampton Classic, Bridgehampton. Call: 631-537-3177.