Dave Matthews, Gwen Stefani, Harry Hamlin in Las Vegas over weekend

By Melissa Arseniuk (contact)

Monday, May 11, 2009 | 11:39 a.m.

Dave Matthews started what proved to be a star-studded Las Vegas weekend early on Thursday as he and a group of about 60 friends joined Stefan Lessard at Playboy Club to toast the bassist’s birthday.

Lessard and Matthews’ bandmates, trumpet-player Rashawn Ross and saxophonist Jeff Coffin, celebrated alongside the others in advance of their Friday-Saturday night concerts at MGM Grand.

Actor Jason Biggs of “American Pie” fame was also there to join the festivities.

Lessard and his entourage drank FIJI water, Ketel One cocktails, Perrier Jouet Champagne and beer throughout the night. Later, a Marilyn Monroe impersonator was brought in to sing “Happy Birthday” and present Lessard with a sparkler-topped birthday cake.

The party shifted into high gear when the quartet of musicians were each given one of the club’s highly-coveted keys. However, the birthday boy and his wife later snuck upstairs, to Moon, to enjoy a slightly quieter end to the evening with a much smaller group of friends.

Also at the Palms on Thursday, “Star Trek” actor Clifton Collins celebrated the premiere of his new movie at Ghostbar with a few rounds of shots (and beer) out on the patio.

While the stars partied en masse at the Palms, Jason Mraz chose a quieter night -- and the circus over the meat market – on Thursday and decided to stick close to MGM Grand.

Mraz, who opened for Matthews on Friday and Saturday and headlined a late-night show of his own at the Pearl on Saturday, took a seat at the 9:30 p.m. showing of Cirque du Soleil’s Asian-themed tale, “KÀ.”

While his bandmates and production staff also took in the show, a reportedly “striking” companion sat next to the singer as he nibbled on popcorn throughout the performance.

Vegas also proved to be the place to be for chefs to see and be seen (and taste and be tasted) this weekend as the annual Vegas Uncork’d took over the city’s culinary landscape.

Many of the nation’s top chefs were at the Wynn on Friday night for a very special and star-studded blackjack tournament.

Tom Colicchio (of both Craftsteak and “Top Chef”), Bobby Flay (of Mesa Grill, and the Food Network’s “Iron Chef America” as well as his own show, “Throwdown”), Joël Robuchon (of Joël Robuchon and L’Atelier de Joël Robuchon) and recent James Beard Award-winner Paul Bartolotta (Bartolotta Ristorante di Mare) were among the tournament’s celebrity chef competitors.

The prestigious James Beard award isn’t all Bartolotta won this past week: He also claimed the tournament’s top prize -- for the second year in a row, no less.

Meanwhile actress Sara Paxton, whose new series, “A Beautiful Life,” is about to debut on the CW, made things official on Friday as she celebrated her 21st birthday at Privé.

The fresh-faced actress was in good company, too, as nightlife veteran/music producer/club host extraordinaire, Jermaine Dupri, was on hand as he reassumed his role as nightclub host and performed yet another “special set” as guest DJ.

Paxtron’s co-stars, Ben Hollingsworth and Jordan Woolley also joined her.

As Paxton and Dupri partied at PH, “Fantastic Four” actor Chris Evans celebrated a friend’s birthday in style few blocks north along The Strip, at Lavo.

Over at the Palms,Danny Masterson, a.k.a. Steven Hyde from “That ‘70s Show,” entertained the masses at Rain for nearly three hours as he reappeared in Las Vegas for a second consecutive weekend and once again adopted his musical moniker, DJ Mom Jeans.

The 33-year-old actor-turned-DJ reportedly preceded his hours-long performance at Rain with a dinner N9NE Steakhouse earlier that evening.

Also on Friday, “Everybody Loves Raymond” costars Ray Romano and Brad Garrett gave their first of two performances at the Mirage.

After the show, the duo were spotted at the resort’s signature nightclub, Jet. “Rock of Love Bus 3” winner (and Penthouse Pet of the Year) Taya Parker also chose Jet as her place to party on Friday.

Maxim cover girl and “Watchmen” starlet Malin Akerman celebrated her 30th birthday at Privé the following night, on Saturday, while NBA All-Star Shawn Marion celebrated a birthday of his own at Pure.

Former MTV VJ and “Entertainment Tonight” personality Vanessa Minnillo was among his party guests.

St. Louis Rams running back Steven Jackson and "For the Love of Ray J” contestant/star Naturalle also partied at Caesars on Friday, at Poetry.

Sean “Diddy” Combs, meanwhile, made it two consecutive weekends of parties in Vegas as he once again enjoyed center stage at Lavo on Saturday. His girlfriend, Cassie, joined him.

Combs “Get Him to the Greek” co-star, Jonah Hill, also had a table at the club that night.

While Combs stuck to Ciroc vodka, Hill drank Carona as he partied well into the morning hours; he didn’t leave until after 3 a.m.

Combs and Hill partied together on Friday night, too, at Privé.

Next door at Lavo’s big sister mega club, Tao, Chris Evans had a very Tao-filled day, first taking in the sun and scenery at Tao Beach before dinner and, finally, a VIP table in the club.

While “Momma’s Boys” actor Rob Kluge was spotted at Tao Beach on Saturday afternoon, two of Vegas’ more common famous faces, David Spade and Mike Tyson, were seen dining at Tao, separately, that night.

Over at the Palms, singer-songwriter Colbie Caillet partied at Playboy Club on Saturday. Joined by a group of six friends, Caillet drank Ketel One cocktails as she enjoyed the nightspot’s sultry surrounds.

Actor Harry Hamlin and his picture-perfect wife, current Playboy cover model Lisa Rinna, celebrated both their 12th wedding anniversary and Mother’s Day in Las Vegas.

The couple was first spotted having dinner at Society Café at Encore on Friday night, enjoying doughnut bites and XXXL chocolate cake for dessert.

After the meal, they took their parents and daughters to see “Le Reve.”

Later that night, the pair celebrated their fete with a just-the-two-of-us evening at Blush.

The next morning, Hamlin, Rinna and family returned to Society for Mother’s Day brunch.

The group was said to have enjoyed the café’s sticky buns as part of their midmorning mom-honoring meal.

Gwen Stefani also celebrated Mother’s Day in Las Vegas this weekend. She and son Kingston Rossdale took in the 9:30 p.m. performance of Cirque du Soleil’s Beatles-themed production, “Love.” Stefani’s bandmates, Gabriel McNair, Tony Kanal, Stephen Bradley and Tom Dumont joined mom and son for the performance.

After the show, the group went backstage to meet the cast and crew.

No Doubt will perform at Mandalay Bay this coming Saturday as part of Tiger Woods’ day-long concert event, Tiger Jam.

Though the weekend is over the star-sighting action will continue tonight as Fat Joe takes over Privé’s Monday night main event, We Rock Hip Hop.