New York, New York - Olivia Rodrigo kicked off her stay at the iconic Madison Square Garden with a bang as she surprised the crowd with a special appearance from Noah Kahan.

The 21-year-old pop star played the first of four shows in New York City on Friday as part of her sold-out GUTS World Tour.

After playing Can't Catch Me Now, Olivia made a surprise addition to the setlist as she welcomed the 27-year-old Dial Drunk artist to the stage.

The two sang Noah's smash-hit Stick Season as a duet, delighting fans in the arena and sparking the most intense envy from Livies stuck watching the footage through social media.

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"Olivia rodrigo is such a special talent and person and I just can't thank her and her band and team for inviting me to sing tonight," Noah tweeted after the show. "You deserve it all."

Though the performance marked their first duet together, the musicians inadvertently collaborated with their BBC Radio 1 Live Lounge covers last year.

For Olivia's appearance on the radio segment last October, she played a cover of Stick Season along with several live renditions of her own hits.

Noah then returned the favor in November by playing lacy from the Disney+ star's sophomore album, GUTS, as his cover.

In February, the pair announced that both covers were being released on a joint vinyl that will drop exclusively for Record Store Day on April 20.

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Olivia continues her stint in the Big Apple with performances on Saturday, Monday, and Tuesday.

If you're looking to get in on the excitement, be sure to check out the buzzy NYC afterparties being held in honor of her MSG shows over the weekend!