Novak Djokovic said playing without pain for the first time at this year's Australian Open on Monday had given him the belief that his hamstring would hold out in his hunt for a 10th title at Melbourne Park and 22nd major to match Rafa Nadal.
The Serbian fourth seed, who sustained the injury en route to the Adelaide International 1 title earlier this month and has been managing the problem, mowed down Australian Alex de Minaur 6-2 6-1 6-2 to reach the quarter-finals.
"A week ago I didn't really think about the title, I just thought about being in a good enough condition to play the next match. Tonight, the way I played, the way I felt gives me reason to believe I can go all the way," Djokovic told reporters.
"I mean, I always believe I can go all the way in terms of my Tennis. But the way my leg felt before tonight wasn't giving me too many hopes, so to say, for the entire tournament, to go all the way through."
Djokovic looked hampered by the problem in previous matches and described Monday's win over De Minaur as his best match of the year but he conceded later that it had been tiring to get himself ready for matches.
"We take it day by day. We do a lot of things actually. It's been exhausting to be involved in a lot of different treatments and machines and stuff that we do," Djokovic told reporters.
"At the same time it was necessary... in order to get myself in a condition to play. So I'm really glad my body has responded really well.
"Tonight I didn't feel any pain. I moved as well as I have the whole tournament. It means we're progressing in the right direction."
Djokovic said he would not celebrate too early as he did not know how his body would respond for his next encounter, against Russian Andrey Rublev.
He explained that his injury meant certain movement had been affected in his previous matches.
"Particularly the extreme movements on the court, change of directions and so forth. Maybe people who were watching me play don't maybe get that idea. For me as a player, being on the court, I can feel the difference," Djokovic said.
"I guess you have to accept and deal with the fact that you have a certain amount of the pain, which isn't an issue for me. The biggest issue was the unpredictability of what the next quick move can cause.
"That's what was my biggest concern because that's how I got injured actually before the tournament started. So those quick change of directions and movements have been in the first couple of matches tough for me. But tonight, no problem at all."