Lucas Pouille became the first Frenchman to reach the semi-finals of the Australian Open since Jo-Wilfried Tsonga in 2010 when he stunned Canada's 16th seed Milos Raonic on Wednesday.
Pouille, the 28th seed, fought back from a break down in the first set to win 7-6 (7/4), 6-3, 6-7 (2/7), 6-4 and reach the last four of a Slam for the first time.
The 24-year-old had never won a match at Melbourne Park before this year but will on Friday face either Novak Djokovic or Kei Nishikori for a place in the final.
Pouille recently recruited 2006 Melbourne Park champion Amelie Mauresmo to his team after a splitting with long-time coach Emmanuel Planque in the off-season.
But the world number 31 came into Melbourne in poor form: he had lost all three of his singles matches at the Hopman Cup and suffered a first-round exit at the Sydney International.
"I'm very happy," Pouille said. "I was trying to forget the start of the year.
More From This Section
"I just kept working hard. All the matches I decided to take step by step, give everything on every point and here I am.
"Last year I lost a bit of joy being on the court," he added.
"I started a new adventure with my team, with Amelie. I enjoy being on the court again and that is the most important." Former world number three Raonic raced to a 3-0 lead after breaking Pouille's first service game as the Frenchman seemed to take a few minutes to adjust to the magnitude of the occasion on Rod Laver Arena.
Pouille soon settled into the match so effectively that he not only broke back at 5-3 down but he also held break points again at 5-5.
Raonic resisted to take it to a tiebreak but Pouille had the momentum and secured the set on the back of 18 winners to only five unforced errors.
"I really wanted to return as much as possible and make him play, take care of my serve and not put too much pressure on myself," said Pouille. "I just enjoyed the moment."