"USA" was the category and the clue was, "These 2 mayors gave their names to a facility built on the site of an old racetrack owned by Coca-Cola magnate Asa Candler."
When the camera focused on Roach during the 30-second time limit for the round, she looked a little unsure and took a while to write down her response.
After time was done, the third-place contestant wasn't correct but the second-place contestant was, responding with "Who are Hartsfield and Jackson?"
Host Ken Jennings explained that they are the namesakes of the airport in Atlanta, Georgia.
"Obviously, for a Georgia native maybe that's not so hard," he said to the contestant who got it right. "But remember, these questions are written months in advance and assigned randomly to games before we even know who the contestants are."
He also gave that disclaimer when the Final Jeopardy! clue from May 3 was about "O Canada" — which Roach got correct.
The second-place contestant wagered $4,200 which brought their total for the game to $15,600. Then it was Roach's turn to reveal her response.
"Did she know it was Hartsfield and Jackson?" Jennings asked before her response was shown.
"Absolutely not," Roach replied with a laugh.
She wrote down, "Who are Churchill and Downs? Idk."
Roach wagered $3,601 which brought her total for the game down to $15,599, knocking her out of first place by $1 and ending her 23-game winning streak.
The Canadian champion's total winnings for her time on the show are US$560,983 which works out to just over CA$722,400!
"Mattea Roach, it has been a pleasure watching you play the game. You finish your remarkable streak in the top five all-time for both longest Jeopardy! streaks and most money won. Congratulations to you and we'll see you in the tournament of champions," Jennings said.
Only Jennings, Amy Schneider, Matt Amodio and James Holzhauer have won more games or money than she has during their time on the show and Roach is the most successful Canadian player of all time.
In an interview after her last game, Roach went through her time on the show including her emotional first win.
"I'm trying not to cry 'cause like my student loan being paid off was like the biggest possible thing that I could've dreamed of when I came down here so to have that happen in the first game was just the most incredible feeling," she said.
Roach hopes people remember her as a player who "was a lot of fun to watch."
The final Jeopardy question on Monday, February 19 featuring a Canadian question. Sarah Rohoman | Narcity