Kyle Edmund says the belief is growing as he prepares to take on third seed Grigor Dimitrov in the Australian Open quarter-finals on Tuesday.
The pair meet during the day session on Rod Laver Arena, not before 03:30 GMT.
Britain's Edmund, ranked 49th in the world, is through to the last eight of a Grand Slam for the first time after two five-set wins in four matches.
Dimitrov, 26, has won both of their previous matches, including a three-set win in Brisbane two weeks ago.
Edmund, 23, rolled his ankle in the final set of that match, prompting Dimitrov to hurdle the net and race to his aid before play later resumed and the Bulgarian clinched victory.