Celine Dion has returned to the stage for the first time since revealing a serious health condition, delivering a typical powerhouse performance at the Paris Olympics opening ceremony.

The Canadian superstar had been rumoured to be singing a duet with Lady Gaga, but instead went solo on the Eiffel Tower to bring the four-hour event to a stirring climax.

It was Dion's first live performance in four years and came a year and a half after she revealed a diagnosis of Stiff Person Syndrome (SPS).

SPS is a rare neurological disorder that causes muscles to spasm and can be debilitating. It also affected her distinctive, forceful voice.

The 56-year-old, known as the "queen of power ballads", has been having therapy to "rebuild" her voice, she told the BBC in June.

On Friday, her delivery of Edith Piaf's classic L'Hymne à l'Amour gave encouraging signs that the treatment is working.

She was accompanied by a pianist on the first level of the Eiffel Tower, beneath giant illuminated Olympic rings.

Canadian Prime Minister Justin Trudeau said that she "is a Canadian icon, an incredible talent, and she overcame a lot to be there tonight".

He added: "Celine, it’s great to see you singing again."

Italian singer Laura Pausini wrote: "My hands were shaking and my eyes were crying as I listened and saw my beloved Celine Dion."

Her appearance had been hotly anticipated, with crowds of fans waiting outside her hotel in the city in recent days.

Dion has a big following in France. Her 1995 album D'eux is the best-selling French-language album of all time.

Friday's appearance was the second time that Dion, known for hits including My Heart Will Go On and It's All Coming Back to Me Now, had participated in an Olympic opening ceremony, after Atlanta 1996.

And her comeback performance came six months after a surprise appearance to present an award at the Grammys.

She has also teased a new residency in Las Vegas.

"We have been working so hard to put this show together - because I’m back," she told the BBC in June.

She already holds the record for the most successful residency of all time on the Las Vegas strip.

Last month, she discussed her struggles with SPS in a film called I Am: Celine Dion, which Amazon Prime Video said on Thursday had become its most successful documentary ever.