The way she saw it, Pegula had much more to lose.
Had she bowed out to the defending champion and lost the wager, Pegula would have had to don a Kansas City Chiefs jersey - quite the ask for someone whose billionaire family owns their storied NFL rivals the Buffalo Bills.
"This team has owned us in the post-season," said the 31-year-old Pegula.
"Absolutely that would have been worse.
"I think that was really some extra motivation because that would have been a tough moment for me."
The victory was Pegula's 13th in her past 14 encounters against fellow Americans and she gets the chance to extend that domestic domination in the quarter-finals on Wednesday against Amanda Anisimova.
The fourth-seeded Anisimova made light of a pro-Chinese crowd on John Cain Arena to oust plucky Wang Xinyu 7-6 (7-4) 6-4).
"I'm feeling great," said the 24-year-old Anisimova, who reached the Wimbledon and US Open finals last year but had not been further than fourth round at Melbourne Park in six previous attempts.
"What a battle out there against a great opponent.
"There were a lot of fans from China today.
"Honestly, it made the atmosphere so great. I don't find it disrespectful �at all."
Fifth seed Elena Rybakina from Kazakhstan needed only one hour and 17 minutes to see off the challenge of Belgian Elise Mertens 6-1 6-3.
The high-water mark of Mertens' grand slam career came at Melbourne Park back in 2018, when she advanced to the semi-finals.
But she was no match for 2022 Wimbledon champion and 2023 AO finalist Rybakina, who will play six-time grand slam champion Iga Swiatek after the Polish second seed ended the dream run of Australian qualifier Maddison Inglis 6-0 6-3 on Monday night.
Pegula jumped out of the blocks against Keys on Rod Laver Arena and raced through the first set in 31 minutes.
A US Open runner-up in 2024, Pegula then went up a double-break at 4-1 in the second set before No.9 seed Keys staged a mini-revival.
But it was too little too late, with Pegula clinching the victory on her first match point.
Keys had won her previous 10 matches at Melbourne Park, including her title run last year, which was capped by an upset victory over two-time defending champion Aryna Sabalenka in the final.
That was the last time Keys had beaten a top-10 opponent and she was unable to snap that streak on Monday.
"Honestly, I'd say it feels way better losing and still being defending champion, because it means you've won," said Keys.
"It's not like the world is ending because I lost today.
"I have 11 months of the year left, and there is still lots to be proud of, and I'm still going to go out and work on new things and try to implement them in the next tournament.
"Obviously disappointed, but I'm really trying to not live and die on every single win and loss at this point in my career."
She's not going to welch on digesting the dodgy pie either.
"A bet is a bet, so I'll do it," said the 30-year-old.
"I hope it's less gross than I think it's going to be, but we'll find out, I guess."
