Miami - Belarussian Victoria Azarenka produced some sparkling tennis to defeat an out-of-sorts world number two Kim Clijsters in the quarter-finals of the Sony Ericsson Open on Wednesday.
Azarenka, whose career breakthrough came with her win here at Key Biscayne in 2009, ran out 6-3 6-3 winner against the 2010 champion Clijsters.
The eighth-ranked Azarenka took full advantage of a below-par display from Clijsters who made 44 unforced errors, a day after she was pushed to a third set tie-break by Ana Ivanovic.
"I just didn't feel good out there. Just mentally and physically, I didn't feel right," the Belgian told reporters.
"It has been a tough few last days but not in a way that I should not be ready for that. I train hard enough to physically be capable of doing that.
"Mentally I just kind of feel like I didn't have any fighting spirit.
"It's obviously tough against someone like her. Against some lower ranked players maybe it's possible to get through matches, but against somebody like her it isn't," she said.
Azarenka, playing good all-round tennis, had a spring in her step on a venue where she first emerged as a player to watch on the tour.
"I feel like I'm happy all the time. It doesn't matter whether I'm on or off the court.
"Here there is so much excitement from people and so many great fans coming. It's always going to be a special place for me, so I'm really enjoying my time here," she said.
"I'm really happy with the way I've started to play. I'm really happy on the court. When you enjoy playing, it makes it a lot easier to be there".
Azarenka will face Russian world number three Vera Zvonareva in the semi-finals on Thursday after she beat Poland's Agnieszka Radwanska 7-5 6-3.
The Russian took advantage of some mediocre serves from her opponent to go up 6-5 in the first set and although Radwanska rallied in the next game to go up 30-0 against serve, Zvonareva regained her composure to wrap up the first set.
It was easier going in the second and the Russian finished off the ninth-seeded Radwanska with a perfect passing shot.
Russian Maria Sharapova will face emerging German talent Andrea Petkovic in Thursday's other semi-final.