John, 69, played "Don't Let the Sun Go Down on Me," a song that the pair had memorably dueted on in 1991.
The singer fought back tears as he told the audience, "I only wish George was here to sing it with me," the Mirror reports.
George Michael and Sir Elton John attend a charity performance benefiting the Elton John AIDS Foundation's newly created Elizabeth Taylor Memorial Fund at the Royal Opera House on November 6, 2011 in London, England. Caroline True/Getty Images
Sitting at a piano, he sang the 1974 ballad as a large picture of Michael, who died on Christmas Day at the age of 53, was projected on the stage behind him.
"There were thousands of us in tears, and it was very emotional," a concertgoer told the Daily Mail. "Elton had sung a song in memory of John Lennon when he spoke about George Michael. After he sang for George, he turned his back on the audience and was shaking and looked like he was crying. I was in tears and so was everyone around me."
Christy Turlington Recalls Working With 'Shy' George Michael Carrie Fisher '20/20' Special: Five Biggest Surprises George Michael '20/20' Special: Seven Biggest Revelations
The concertgoer told the Mail that John was consoled by a band member after the crowd gave him a standing ovation.
Fans posted footage from the tribute online with one writing, "Such a beautiful and moving dedication to #georgemichael by the amazing incomparable #eltonjohn #sireltonjohn Seriously one of the best concerts I've ever had the pleasure of attending. Thank you."
As previously reported, the former Wham! singer was found dead in his London home on Christmas morning. While autopsy results are pending, Michael's longtime manager said in an interview with The Hollywood Reporter that the '80s heartthrob had died of heart failure.
Shortly after Michael's death was announced, John took to Instagram to write a tribute to his close pal. "I am in deep shock. I have lost a beloved friend — the kindest, most generous soul and a brilliant artist. My heart goes out to his family, friends and all of his fans."
There are unconfirmed reports that John will be among the performers singing at Michael's funeral in the U.K.
Want stories like these delivered straight to your inbox? Sign up now for the Us Weekly newsletter!
We thank you for your visit and this news was published from the source us-magz us-magz
Get the latest news delivered to your inbox
Follow us on social media networks