The gripping 7-6(5), 6-7(5), 3-6, 7-6(3), 6-4 clash spanned five hours and 26 minutes to earn the world No.104 an elite eight encounter with fellow Italian Matteo Berrettini.
In doing so, Arnaldi has spent a tournament-leading 17 hours and 42 minutes and counting on court this fortnight.
“I don’t know how I’m standing here to be honest,” said a jubilant Arnaldi. “We live to play these matches. I always dreamed to play matches like this, at Roland-Garros, at night, in these battles against someone like Frances.
“I think at one point it wasn’t tennis, it was just something else, you just played with everything you had. There had to be a winner and fortunately it was me tonight.
“This is definitely the best match I ever played.”