Alex Trebek's last great "Jeopardy!" champion has died at the young age of only 24.

Brayden Smith, who scored a 5-game winning streak and more than $115,000 in winnings as Trebek's era came to a close, died unexpectedly last Friday in his hometown of Las Vegas. The cause of death is unclear.

Brayden's lifelong dream had always been to appear on "Jeopardy!" ... and the young man, who had reportedly tried getting on the show at least a dozen times, left a lasting impression on Trebek and fans alike.

His run was so impressive he drew comparisons to the great James Holzhauer because he also had a knack for finding the Daily Doubles and laying huge wagers when he did.

Trebek was very much impressed with Brayden's prolific run ... dubbing him "Billy Buzzsaw" for his ability to dismantle the competition. Trebek also uttered "Most impressive. I don't know what to say." Brayden, of course, appeared in the final shows Trebek ever hosted before he died from pancreatic cancer.

Brayden, who died about a month after his episode aired, had been looking forward to competing in the show's Tournament of Champions. He had just graduated from UNLV last year with a degree in economics and had hoped to attend law school and become a U.S. Attorney.

The family's asked that donations be made in Brayden's name here ... a fund benefiting Nevada students furthering their education.

RIP, Champ.