O’Hare Airport Tuesday christened a new $4.8 million gate, designed to accommodate the world’s largest commercial jet, by test-landing an Emirates Airbus 380, the model made famous in Jennifer Aniston commercials.

The double-decker luxury liner used the new gate, M11 A, to disembark arriving first-class and business-class passengers from Dubai via a second-story loading bridge.

Lower-level economy passengers used a traditional height loading bridge at gate M11.

“They had to adjust some minor things, but it did connect,’’ Emirates ground staffer Moin Nizami said of the new second-story loading bridge. “It took a little longer because we wanted to be cautious.”

Chicago Aviation Commissioner Ginger Evans called the gate’s christening, complete with a shower from water cannons, a “milestone.”

O’Hare now joins the ranks of airports in Los Angeles, Washington, D.C., New York City, Miami, and San Francisco that have at least one gate large enough for the wide-bodied Airbus 380, which is designed to carry more passengers on longer hauls, Evans said.

A second such gate is expected to be among the nine new gates planned for O’Hare’s Terminal 5, Evans said.

Plus, a new runway planned in the north section of the airfield will have both the length and the width to accommodate an A380, as did runway 10C in the south airfield on Tuesday, Evans said.

Emirates currently operates 81 Airbus 380s, more than any other airline, said Rob Gurney, Emirates senior vice president of commercial operations in the Americas. So the airline was delighted when O’Hare asked it about six weeks ago if it would test out the new gate, and Emirates swapped out a planned 777 flight with its flagship Airbus 380 to do so, he said.

Emirates’ version of the A380 holds just under 500 passengers, up from 350 on its next biggest jet, a Boeing 777, Gurney said. The double-decker boarding bridges required for such massive jets allows both decks of passengers to board or disembark simultaneously.

Airlines using O’Hare’s Terminal 5 agreed to bankroll the gate as part of their terminal user fees but specifically asked that the loading bridge have the flexibility to be lowered and used at a traditional height as a second boarding bridge for non-A380s, said David Woodcock, who represented the International Terminal airline parties in that deal.

Emirates’ configuration of the world’s largest commercial liner features a first-class spa-shower area and a sleek circular bar featured in commercials with a bathrobe-clad Anniston, who suffers an onboard nightmare by dreaming that she’s on a plane without such luxury.

“It’s a cool plane. It’s so different,’’ Evans said. “It’s intended to relax people because it’s designed for longer flights.”

Evans said she has never flown first class on an Emirates A380 because the business class, also located on the upper deck, is “par excellance.”

Even business-class features fully reclining seats, private TV screens, an ottoman, an iPad and a free personal beverage/snack bar at each seat. First-class seats boast all that and more, in an even roomier setting, called a “suite,” plus access to a spa-shower.

No U.S. airline yet operates an Airbus 380, but Emirates, Lufthansa and Korean Air at a minimum have expressed interest in the new A380 gate, Evans said. No deals have yet been struck but O’Hare hopes to open the gate to regular routes this fall, she said.