The opening ceremony at the Winter Games hit a bump when only four of the five rings materialized in a wintry opening scene. The five were supposed to join together and erupt in fireworks. But one snowflake never expanded, and the pyrotechnics never went off.

But everything worked fine for viewers of the Rossiya 1, the Russian host broadcaster.

As the fifth ring got stuck, Rossiya cut away to rehearsal footage. All five rings came together, and the fireworks exploded on cue.

"It didn't show on television, thank God," Jean-Claude Killy, the French ski great who heads the IOC coordination commission for the Sochi Games, told The Associated Press.

Producers confirmed the switch, saying it was important to preserve the imagery of the Olympic symbols.

The unveiling of the rings is always one of the most iconic moments of an opening ceremony, and President Vladimir Putin has been determined to use the ceremony as an introduction of the new Russia to the world.

Konstantin Ernst, executive creative director of the opening ceremony, told reporters at a news conference that he called down to master control to tell them to go the practice footage when he realized what happened.

"This is an open secret," he said, referring to the use of the pre-recorded footage. The show's artistic director George Tsypin said the malfunction was caused by a bad command from a stage manager.

Ernst defended his decision, saying that the most important part was preserving the images and the Olympic tradition: "This is certainly bad, but it does not humiliate us."

NBC was to air the ceremony in the US on tape delay later Friday, and said in a statement: "We will show things as they happened tonight."

Glitches are not uncommon at Olympic opening ceremonies.

There was a minor controversy over trickery involving the fireworks at the opening ceremony of the 2008 Beijing Olympics, after it was revealed that some of the display featured prerecorded footage.

Fireworks bursting into the shape of gigantic footprints were shown trudging above the Beijing skyline to the National Stadium near the start of the ceremony. Officials confirmed that some of the footage shown to TV viewers around the world and on giant screens inside the stadium featured a computer-generated, three-dimensional image.

In addition, a tiny, pigtailed 9-year-old girl in a red dress who sang "Ode to the Motherland" was lip-synching. The real voice belonged to a 7-year-old girl who was replaced because she was deemed not cute enough by a member of China's Politburo.

At the 2006 Winter Games in Turin, Luciano Pavarotti's performance was prerecorded. The maestro who conducted the aria, Leone Magiera, said the bitter cold made a live performance impossible.