ET was at the star-studded event when the 68-year-old "Candle in the Wind" singer celebrated the late musician's legacy with a touching, instrumental cover of Bowie's 1969 classic "Space Oddity."
The simple, elegant cover was the only song John performed without lyrics, his band, or an intricate lighting design -- it was just John paying his respects to the memory of a beloved, influential fellow artist.
John then transitioned from Bowie's classic into his own megahit "Rocket Man" and brought the house down.
The living legend also tipped his hat to the next generation of musical artists, welcoming out several high-profile guests to perform duets of some of his biggest hits.
"Confident" singer Demi Lovato killed it when she joined John for a performance of his 1979 classic "Don't Go Breaking My Heart."
The 23-year-old singer worked the stage during the lively number, strutting around the six-time GRAMMY winner and his crimson piano.
Fall Out Boy frontman Patrick Stump also joined John on stage for a super high-energy performance of his 1973 single "Saturday Night's Alright (for Fighting)," which the band had recorded of cover of in 2014.
John also welcomed "Stitches" singer Shawn Mendes, and the two performed a moving duet of "Tiny Dancer."
ET caught up with Mendes at the star-studded after party -- where Teen Wolf actor Charlie Carver, singer Jake Shears and comedian Marc Maron were in attendance -- and the 17-year-old star shared that the once-in-a-life experience was "unbelievable."
John isn't the only musician who's paid tribute to Bowie in the days since he died. On Tuesday, Madonna honored the groundbreaking entertainer with a cover of his beloved single "Rebel Rebel" during her concert in Houston, Texas.
Many other stars shared their grief and the memories of Bowie on Twitter as well. Check out the video below for a look at the tributes celebs posted in the wake of Bowie's death.
Elton's upcoming album, Wonderful Crazy Life is out Feb. 5.