A shopping trip to go buy pantyhose with his mother turned into a "fluke dream come true" for a 23-year-old mega-fan from Welland, Ont., after a chance encounter with the lead singer of Aerosmith.

Anthony Yorfido, who has Down syndrome, unsuccessfully tried getting tickets for a pair of sold-out Steven Tyler solo shows at the Fallsview Casino in Niagara Falls this past week.

But his luck changed when Yorfido and his mother, Diane, happened to bump into the rock star last Thursday while shopping at a medical supplies store in Niagara Falls.

"I was picking up my pantyhose and I saw a stretch limo outside… I went in and Steven Tyler was leaned over on the counter and he had a couple ladies with him," Diane Yorfido told CBC News.

"Anthony was standing behind me … [and] he just said, 'Oh my god.' He went nuts. He goes, 'Is that Steven Tyler?' Like he totally knows him because he loves Aerosmith, he loves Steven Tyler. He listens to his music all the time."

Anthony Yorfido happened to bump into the rock star last Thursday while shopping with his mother at a medical supplies store in Niagara Falls. The two hugged and posed for photos together. (Photo courtesy of Diane Yorfido)

Anthony Yorfido, who describes himself as a "really, really, really, really, really, really big" Aerosmith fan, says he recognized Tyler immediately. He would watch him all the time when Tyler was a judge on American Idol.

"I knew it was him because I saw the back of him. I saw the limo outside. I knew. I saw his ponytail."

The two hugged and posed for photos. They say the singer was at the store picking up a back brace. When Tyler found out the family couldn't get tickets, he offered them backstage passes to that night's show.

Performing on stage

Diane Yorfido had to work, so Anthony ended up going to Thursday's show with his dance instructor, Jordan Setacci. The two got to watch from the side of the stage.

As Tyler kicked off his set with the Aerosmith tune Sweet Emotion, he invited the 23-year-old on stage with him to rock out with a pair of yellow shakers.

Tyler held the mic to Yorfido's shaker, before yelling out "Anthony in the house" and continuing with the song.

Anthony Yorfido ended up rocking out on stage to Sweet Emotion with Aerosmith front man Steven Tyler after a fluke encounter while out shopping with his mother. (Photo courtesy of Jordan Setacci)

"I was shocked. I didn't know I was going on stage," Anthony Yorfido told CBC News. "I was really, really excited to meet him. It was my dream come true."

A video of their impromptu performance has been posted online and Yorfido's story has since gone viral. He says his friends and family are "going nuts" over it all.

Anthony's a 'new friend'

Tyler has been known to surprise his Canadian fans. Last summer, he played Dream On in a Kelowna, B.C., park using one of the city's free outdoor pianos. A week later, he mingled some newlyweds in Edmonton.

The Yorfido family has been keeping in touch with Tyler's crew since Thursday, sending them photos of the meeting and performance via text message.

The Aerosmith singer held the mic to the shaker playing before yelling out 'Anthony in the house.' (Photo courtesy of Jordan Setacci)

Diane Yorfido says she hopes they can remain in contact with the lead singer and perhaps meet him again sometime soon.

She says she and her son are still in disbelief.

"He just stopped in to get a back brace because his back was sore and he said to me, he said, 'I didn't stop in here to get a back brace ... I stopped in here to meet my new friend Anthony,'" she said.

"What a wonderful, wonderful man."