Elton John Pays Emotional Tribute to George Michael During Vegas Concert

This video is unavailable because we were unable to load a message from our sponsors.

If you are using ad-blocking software, please disable it and reload the page.

Elton John is mourning the loss of his good friend, George Michael.

The 69-year-old singer opened his Las Vegas show on Wednesday with a performance of his hit, "Don't Let the Sun Go Down on Me." The two superstars memorably sang the song together in a live cover version in 1991, which reached number one in both the U.K. and the U.S.

John sang the ballad as a picture of Michael was projected in the background.

WATCH: James Corden Pays Tribute to George Michael, Who Helped Inspire 'Carpool Karaoke'

"I only wish George was here to sing it with me," John told the audience, appearing to be in tears, according to The Daily Mail.

"After he sang for George, he turned his back on the audience and was shaking and looked like he was crying," an eyewitness also tells the outlet. "He received a standing ovation and had to be consoled by a band member before beginning the rest of the show. There wasn't a dry eye in the house."

Check out their original performance of the heartfelt tune below:

On Monday, John tweeted about Michael's death. "I am in deep shock," he wrote. "I have lost a beloved friend -- the kindest, most generous soul and a brilliant artist. RIP @GeorgeMichael."

WATCH: George Michael's Wham! Bandmate, Andrew Ridgeley, Remembers the Late Singer

Michael was found dead at his home in England on Christmas morning by his boyfriend, celebrity hairstylist Fadi Fawaz. He was 53 years old.

Watch below: