The 19-year-old Pole produced a devastating performance against the 2018 champion to storm into a maiden Grand Slam quarter-final.
Story so far: Halep, Bertens exit, Rafa unstoppable
Title favourites Simona Halep and Kiki Bertens suffer fourth-round defeats as Nadal crushes Korda
The 54th-ranked Swiatek, a former Wimbledon junior champion and Roland-Garros junior doubles champion, fired 30 winners and won 81 per cent of her first-serve points, wrapping up the win in just 68 minutes.
"I don't know what happened actually, I felt like I was playing perfectly, I was so focused the whole match, even I am surprised that I can to that," an elated Swiatek told Cedric Pioline on court.
Halep, who crushed Swiatek in a 45-minute rout in the French capital last year before falling to American teenager Amanda Anisimova, was on a 17-match winning streak entering the contest on Sunday and has now suffered her earliest Roland-Garros exit since 2016.
"I wasn't experienced at all then, that was my first match on a big stadium like that, so I was pretty stressed," Swiatek said of her fourth-round defeat to Halep last year.
"Since then, I've made huge progress because I've played a few big matches, against Simona, against Caroline Wozniacki and Naomi Osaka, and I think it helped me a lot and now I feel like I can handle the pressure.
"But also I remember I lost against Simona last year and she lost against Amanda in the next round, so I felt that maybe I can do the same scenario, but we just change the names."
Shortly after, on Court Suzanne-Lenglen, another title favourite suffered a shock defeat as No.5 seed Kiki Bertens stumbled out 6-4, 6-4 to Italian qualifier and world No.159 Martina Trevisan in 95 minutes.
"I'm living in a dream. I came here two weeks ago to my Roland-Garros qualifying but today I'm here in the quarter-finals," said the 26-year-old lefty, who is the first Italian woman to make the quarter-finals in Paris since Sara Errani in 2015.
"Oh my God, I can't believe it. I'm really honoured to play in this court with Bertens, because she's an incredible player. I can't believe it."
Trevisan, who saved two match points in her win over Maria Sakkari two days earlier, is making her Roland-Garros debut. After 16 straight losses to top-100 players across all level between 2017 and 2020, she has now posted four consecutive wins over such opponents in one week.
Trevisan and Swiatek will square off in the last eight.
No mercy from Nadal
Later on Court Philippe-Chatrier, 12-time champion Rafael Nadal was ruthless against American qualifier Sebastian Korda as he powered into the quarter-finals 6-1, 6-1, 6-2 after less than two hours of play.
The Spaniard is through to a record 14th Roland-Garros quarter-final, where he faces either sixth-seeded Alexander Zverev or Italian prodigy Jannik Sinner.
Korda, the world No.213 who is the son of 1992 Roland-Garros finalist Petr Korda, was making his debut in Paris this fortnight. The 20-year-old earned many fans with his heroics in the French capital and walks away with lessons learned from his last-16 clash with the King of Clay.