Pop idol Madonna gave it all in Rio de Janeiro as she looked back on her four-decade career in a historic show before throngs of joyful fans jammed onto Brazil's famed Copacabana beach on Saturday night.

The 65-year-old singer walked down an elevated bridge from the Copacabana Palace hotel shortly after 10:30 pm (0130 GMT Sunday) to a massive stage for one of the most important shows of her career.

Dressed all in black, Madonna broke into her hit "Nothing Really Matters" at the start of a burst of brute energy.

"Rio, here we are in the most beautiful place in the world," she said at the start of a performance that brought the giddy Brazilian audience to its feet.

The show marked the final stop on her "Celebration Tour" noting her 40 years atop pop charts, in a free event that was estimated to draw upward of 1.5 million fans from across Brazil.

Billed as a "historic" show, it blended music and dance with cabaret.

Madonna showcased her versatility with dozens of set and costume changes, spectacular lights and many giant screens along the beach.

She went from being dressed as a schoolgirl in a miniskirt to an irreverent Christian in a black cape while luminous crosses circled around her during "Like a Prayer," a song that cost her excommunication from the Catholic Church.

'Live To Tell'

Madonna was joined on stage during the performance of her hit "Vogue" by Brazilian singer Anitta, who is known for taking Carioca funk -- the soundtrack of Rio's favelas -- to the rest of the world.

With "Live To Tell", she paid tribute to AIDS victims, including Freddie Mercury and the legendary Brazilian musician Cazuza.

US electronic dance music master DJ Diplo opened the show as thousands jostled to get a view of the stage. Boats bobbed in the water offshore, letting those onboard enjoy the show.

"I'm a mess, I haven't slept well, I've been listening to Madonna all week," 29-year-old sociologist Ina Odara told AFP. Tattooed on her shoulder was Madonna's phrase: "All that you ever learned, try to forget."

"Madonna helped me leave the Catholic Church, think about many things and change my relationship with my family," said Odara, a transgender woman, standing near the huge stage that was twice the size of any other used on the tour.

Police patrolled almost every corner to minimize the usual mass robberies.

After 80 performances across Europe and North America, the Rio concert provided a crowning touch to a tour that took on sudden urgency when the singer suffered a life-threatening bacterial infection in June last year.

Madonna has released an album every two or three years since the 1984 release of "Like a Virgin."

Her shows, with their spectacular productions, set a high bar. But the ever-provocative Madonna has also provided unforgettable moments, such as when she kissed Britney Spears at 2003's MTV Music Video Awards. 

Her irreverence led to a tumultuous relationship with the Catholic Church, with Pope John Paul II urging fans to boycott her over her provocative 1989 video "Like a Prayer," which was seen as blasphemous.

'Oi, Rio!'

Madonna's concert should provide an economic boost to Rio, which contributed 20 million reales ($4 million) toward the $12 million production cost.

Authorities expected it would pump a far larger sum -- 293 million reales, or $57 million -- into the local economy.

On every corner in the Copacabana neighborhood were billboards, souvenirs or T-shirts bearing images of Madonna or of the conical corset designed by Jean Paul Gaultier and made famous by the diva.

Hundreds of her fans swarmed outside the Copacabana Palace since her arrival on Monday.

The excitement spiked Thursday night when Madonna unexpectedly appeared for a sound check, her face almost completely hidden behind a colorful balaclava. 

That scene was repeated on Friday. 

"Oi, Rio!" she called out in Portuguese to fans.

The response on Saturday night from more than a million voices: "Oi, Queen Madonna!"