Jennifer Lopez and Marc Anthony have renewed their wedding vows.

The couple, who have been married for four years, took part in a vow renewal ceremony at 3:15 a.m. Sunday morning at Caesars Palace in Las Vegas.

The ceremony took place at the newly renovated Forum Tower Penthouse, officiated by Reverend Steven Smith, and with two friends serving as witnesses. The couple were the first to stay in luxe suite since it reopened.

The couple teamed up with New York Mets outfielder Carlos Beltran and his wife Jessica to renew their vows in a joint ceremony, says People magazine.

"Carlos gave his wife a specially engraved ring and gave Marc and Jennifer special rings as gifts," a source tells People. "Carlos and Jessica renewed their vows first, then Jennifer and Marc went."

Before the ceremony, the couples reportedly played and won a game of craps and dined at Bradley Ogden.

The ceremony went off without a hitch, a source tells People, except for a last-minute change that moved the vow-renewal from a balcony to a warmer, indoor climate.

"Marc actually said the suite was so beautiful that it deserved it's own zip code," the source tells People. "He thought it was perfect."

Lopez reportedly wore a black dress, and both couples sipped Dom Perignon champagne to celebrate as twelve people witnessed the ceremony -- not including Lopez's parents, who were watching her twins, says People.

Lopez and Anthony welcomed twins Max and Emme earlier this year.