AceShowbiz - Billy Joel welcomed Bruce Springsteen to the stage for a surprise duet at his landmark concert at New York City's Madison Square Garden on Wednesday night (July 18).

Springsteen made an appearance at the gig to celebrate the "Uptown Girl" singer's 100th Lifetime Performance at the famed venue, perching himself atop of Joel's piano to sing two songs with the star, including his legendary hit "Born to Run".

Joel introduced the rocker by telling the crowd he had a guest coming onstage who has won Grammy, Oscar and Tony Awards, the last, a special Lifetime Achievement Award, which was presented to the star in June.

"Congratulations Billy on your 100th show," Springsteen said, according to Billboard. "Ready, Billy?" he asked, as Joel began to play the opening chords to song "Tenth Avenue Freeze-Out".

After jumping onto Joel's piano, The Boss then rocked out for a duet of his 1975 hit "Born to Run".

According to editors at the news outlet, the music veterans hugged after their two-song performance, and Springsteen kissed Joel on his head before he headed offstage.

In celebration of Joel's 100th performance, bosses at the venue hoisted a banner to the ceiling towards the end of the two-hour long concert.

"Good evening to you New York City," smiled Joel earlier, as his two-year-old daughter, Della Rose, sat on his lap. "I want to thank you all for coming to our show."

"Maybe it'll hit me later," he added of his feat, having first taken to the stage at the iconic venue in 1978.

On Wednesday, Governor of New York City Andrew Cuomo also proclaimed July 18, 2018, as Billy Joel Day.