Cleveland hosted the National Sports Collectors Convention this weekend, and they had a pretty exciting moment Friday.

Leighton Shelton purchased a spot from the Vintage Breaks auction to open up packs of vintage sports cards.  He paid $500 for the opportunity to open a 1955 Bowman baseball pack.  When he got to the second to last card, Sheldon let out a scream.

"My eyes bulged out of my head," Sheldon said.

Sheldon had pulled the most valuable card from the set: a Mickey Mantle in near pristine condition.

After the excitement on Friday, Sheldon returned to the convention Saturday in order to have the card  be graded by PSA, considered the industry's authority on the condition of cards.  Three hours later, PSA returned with a grade of 9 out of 10, which is nearly perfect condition.  (A 10 is the highest grade a card can receive.)  It had been more than two decades since PSA had graded a 1955 Bowman Mantle with a grade of 9, according to Sheldon.

By Saturday at 7 pm, Sheldon had received an offer of $50,000 for the rare card.  A previous 1955 Bowman Mickey Mantle that was a grade 9 sold for $35,089.