Sydney: Kim Clijsters underlined her growing status as the Australian Open favourite with a 6-3 6-2 victory over Victoria Azarenka to reach the Sydney International semi-finals on Wednesday.
The 27-year-old third seed, who won the warm-up event for Melbourne Park twice before her sabbatical from the game to have a child, said, however, that it was far too early to talk about winning the opening grand slam of the year for the first time.
"Favourites, it really doesn't mean anything. Really doesn't," Clijsters told reporters. "Every match and every tournament has to be played. You all start - 128 players start from scratch. It's the same for everybody from the start."
Kim Clijsters defeated Victoria Azarenka while Juan Martin Del Potro was beaten by Florian Mayer.
The US Open champion, the highest remaining women's seed in the draw after the departures of world numbers one and two Caroline Wozniacki and Vera Zvonareva, needed to draw on her experience against the Belarussian.
"I think the score definitely sounds a lot easier than it was," said the Belgian, who will face Alisa Kleybanova in the last four after the Russian beat Dominika Cibulkova 6-3 5-7 6-2.
"I played the important points better ... I think that's obviously a good feeling to have when I'm down breakpoint I can hit a good serve."
Former US Open champion Juan Martin Del Potro's comeback from injury faltered, however, when his lack of match practice was exposed in the men's second round.
The 22-year-old Argentine declared himself free of pain when he won his first match in a year in three sets on Monday but he was well beaten 6-2 7-5 by Germany's Florian Mayer.
"Everything is tough after a long, long time," Del Potro said. "But if I'm here it's because I want to play. I want to try again. That's what I'm thinking every day. I don't want to feel bad, you know.
"Last year was very bad year for me, and now I'm okay. I am in good shape ... I lost, but I'm in the competition again."
Top men's seed American Sam Querrey's tournament lasted just 62 minutes before he was bundled out 6-4 6-3 by Ukrainian Alexandr Dolgopolov.
"The first match of the year, it was very windy out there," said Querrey. "He's a tough guy to play in the wind. He's got a massive serve and kind of slices the ball around."
It was the first time since 2002 that both top seeds had lost their first matches at the tournament.
China's Li Na also confirmed her fine early season form by becoming the first player into the women's semis with a 3-6 7-6 6-3 victory over Russian twice grand slam champion Svetlana Kuznetsova.
The world number 11, who reached her first grand slam semi-final at Melbourne Park last year, fought back from a set and 5-3 down to reach the last four in Sydney for the second time.
"We've played many times," said the 28-year-old. "Maybe at the beginning of the match I didn't have the energy to fight against her but when I was 5-3 down, I woke up again."
Li faces Bojana Jovanowski for a place in the final after the Serbian beat Flavia Pennetta of Italy 6-4 6-1.