Jungels made a gutsy breakaway with 65 kilometres to go in the Tour de France on Sunday (AEST), asserting his lead from the outset and holding off a fast-finishing Jonathan Castroviejo (INEOS Grenadiers) comfortably to win the stage by 22 seconds.
The victory was not only the Luxembourgian's first in the Grand Tour, but also came after a potentially career-threatening condition which had forced the rider out for 93 days of cycling last year.
Shortly after competing in the Tour de Suisse in mid-June, Jungels was struck down with arterial endofibrosis - a condition that reduces blood flow to the legs and one that particularly affects cyclists and other high performance athletes.
He was subsequently withdrawn from competing in both the Tour and the delayed 2020 Summer Olympics, largely struggling upon his return in cycling events before his sixth-placed finish in the Tour de Suisse and victory in the Luxembourgish National Time Trial Championships.
The 29-year-old showed glimpses of brilliance through his 12th-placed finish in the opening stage time trial in Denmark and upon finishing ninth in stage eight, but it all came together for the Luxembourgian on Sunday night (AEST) as he staged a phenomenal breakaway to win the stage.
"It's hard to say how I feel right now, I'm just overwhelmed," Jungels said after the race.
"This is huge, this is what I came here for after a couple of years of struggling, a very tough year last year with surgeries and everything.
"To take the victory this way, it's my style of racing.
"Last few days I felt better and better, yesterday I was in the mix but winning that stage - it's a big step and today I took all the risks I could, and it happened."
Jungels became the first rider from Luxembourg to win a stage at the Tour de France since Andy Schleck in 2011, adding to his career achievements which include wins in the Giro d'Italia young rider classification in 2016 and 2017, as well as an individual stage win in the latter.
The Tour de France now enters a rest day, with racing resuming on Tuesday night (AEST) with a 148-kilometre stage from Morzine les Portes du Soleil to Megeve. Watch all the action live from 9:20pm (AEST) on the SBS SKODA Tour Tracker, or 9:30pm (AEST) on SBS and SBS On Demand.