Grigor Dimitrov beat David Goffin 6-3 6-2 6-4 to progress to the semi-final stage of the Australian Open for the first time.
Dimitrov capitalised on a tentative start from Goffin to cruise into a two-set lead as the Belgian struggled with his range and serve.
Goffin, who cut a passive figure for much the first two sets, made a better fist of the third but Dimitrov secured the decisive – and ultimately match-winning – break in the seventh game.
"In the first set it was absolutely nerve racking," Dimitrov said. "I felt that I could play well but I was not striking the ball as well as I could and I was a bit passive. "With each game I was feeling a bit better and I was finding my groove. I'm just happy now."
The 25-year-old Dimitrov secured the match with a trademark backhand down the line and was ultimately rarely stretched by Goffin who amassed 46 unforced errors in a disappointing two hours and 12 minutes on court.
"I have been on a tremendous roller coaster," Dimitrov said of the last two years.
"But I am happy with the way things happened the way it did, otherwise I wouldn't understand myself and I'm now appreciating things a lot better.
"To be in the semi-final of a slam means too much for me now."
The win means the 15th seed will face either Rafael Nadal or Milos Raonic for a spot in the final.
The former world number eight has now won 10 matches on the spin after the winning the Brisbane International tune up event.