Michigan resident Patrick Setto said he wasn't even sure he would be able to attend Josh Groban's Sunday concert at Caesars Windsor.

Though Setto said he's been a longtime fan of Groban and wanted to attend the show, a busy life got in the way for the Chaldean Catholic priest, so he put the concert to the side.

"My cousin found out that I really wanted to go, so she went ahead and bought tickets," said Setto, who is a priest at Mother of God Church in Southfield, Mich. "I had no idea, she surprised me."

Rushing to cross the border, Setto said he prayed that he and his cousin would be able to meet Groban before the show.

They were unable to meet the musician, but Setto instead got the opportunity of a lifetime: He performed one of Groban's songs in front of the acclaimed musician, stunning both the artist and an audience of more than 4,000 people.

"God [answered] my prayers and let me sing for him," Setto said.

In addition to being a fan of Groban's music, Setto is also a theatre and music buff who performs in a praise and worship band.

Father Patrick Setto performed a rendition of Josh Groban's "To Where You Are." (Submitted by Patrick Setto)

"I discovered I could kind of sing in middle school and … I was always doing theatre in high school," Setto said. "We did some musicals in seminary actually that became really well-known, very popular among the metro Detroit area."

According to Setto, his opportunity came when Groban began taking song requests from the audience.

"He was listening to the crowd," said Setto. "So my cousin looks over and goes, 'Just say I want to sing with you, just scream it out.'"

Groban granted Setto's request, handing him a microphone to sing some of "To Where You Are."

Setto's performance was captured on video and uploaded to YouTube and social media, where it's amassed more than 20,000 views across multiple platforms.

Watch Patrick Setto perform "To Where you Are" in front of Josh Groban and a Caesars Windsor audience:

As the footage shows, Setto's performance astonished both the audience and Groban himself.

"You just gave me a nice little break, Patrick," joked Groban, after Setto returned the mic. "When I come back here in a year, I'm going to be playing in the bar and I'm going to be seeing posters for Patrick."

An audience member later says something to Groban, leading the multi-platinum artist to ask incredulously, "You're a Catholic priest?"

Setto said Groban's personality is one of the reasons why he's such a fan of the musician.

"I've always thought his personality is really down to the Earth," said Setto. "He's a simple guy, he's funny, he knows how to relate to people, and I think his music … has a spiritual message. Whether he intended that or not, the music has got an almost supernatural touch to it."