Angelique Kerber says she doesn't know if she's happy because she's playing well or playing well because she's happy - but either way she'll take it.
The 2016 Australian Open champion stamped her authority on the women's field with a breathless quarter-final win over Madison Keys to march into the last four at Melbourne Park.
The German will take on world No.1 Simona Halep in Thursday's semi-final after the Romanian swept past Karolina Pliskova 6-3 6-2 in one hour and 11 minutes.
The sole grand slam champion remaining in the field, Kerber took just 51 minutes to beat the American 6-1 6-2 in their quarter-final on Wednesday.
The former world No.1 disarmed the heavy-hitting American with power-punching from the baseline and remarkable consistency.
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She made just seven unforced errors for the match and denied the big-serving 22-year-old a single ace.
Kerber felt she was getting back to her best.
"I'm just trying to finding the feeling that I had in 2016 and just enjoying my time, on and off court," Kerber said.
"I think for me, it's really important to just have a good time off court."
The belting was all the more remarkable given Keys' form.
The US Open finalist hadn't dropped a set in four matches leading into the last eight, but saw the first set slip by in a blink of an eye.
In the second set Keys broke Kerber to bring the games back on serve at 3-2 but gave the break back in the very next game.
Racing to the net to hit a volley, Keys over-swung and sent her effort wide, letting Kerber back into a position of dominance and she didn't look back.
Kerber had a tough year in 2017, failing to win a tournament or reach the quarter-finals at any slam after winning the two hardcourt majors in 2016.
"Being in the semis again, it means a lot to me," the 30-year-old said.
"I had a tough year last year, so that's why I think that I'm just looking forward and I'm proud how I get through all the last week and being in the semis again in a grand slam."
She said that going all the way in 2016 in Melbourne gave her confidence about conquering what lies ahead against Halep.
"That also gives me a little bit of confidence that I know what to expect now," Kerber said.
