No. 1 Azarenka suffers first loss of 2012; Venus' return ends

(CNN) -- Women's tennis No. 1 Victoria Azarenka is looking forward to more success despite the end of her perfect start to 2012.

The Belorussian had won 26 successive matches going into Wednesday's Miami Masters quarterfinal -- the best start to a season since Martina Hingis went 37-0 in 1997.

However, the Australian Open champion suffered a shock defeat by French seventh seed Marion Bartoli, who will face world No. 5 Agnieszka Radwanska in Thursday's semis after the Pole ended the comeback of Venus Williams.

"What I've done in the last couple of months, I have to be really proud of myself," the 22-year-old Azarenka told the tournament's official website after her 6-3 6-3 loss.

"I could have maybe played better today, that's for sure, but I gave it all I had. But Marion played really well today, and she deserves the win. What else can I say? I have to look forward."

Defending champion Azarenka had won eight of her previous 10 meetings with the 2007 Wimbledon runner-up, including January's Sydney International where Bartoli lost despite leading in both sets.

"I was up 5-2 in the first set and 4-1 in the second set, and I lost both," the 27-year-old Bartoli said. "So I knew I had to stay really mentally tough and not show her anything.

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"Even when I lost those three games in a row, I didn't get down on myself -- I had this positive energy. I was able to turn the match around again and step inside the court and play some great points."

Fifth seed Radwanska booked her place in the last four with a commanding 6-4 6-1 win over former world No. 1 Williams, who was playing in her first tournament for seven months.

Seven-time grand slam winner Williams had not played on the WTA Tour since withdrawing from last year's U.S. Open, having been diagnosed with Sjogren's syndrome -- an incurable condition which causes pain in the joints and fatigue.

"I didn't have a good day," said the 31-year-old Williams, who has won the tournament three times andw as runner-up in 2010. "Unfortunately, I just couldn't press the issue. I don't feel like she did anything special. I just couldn't. I couldn't get myself to do it today.

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"If I'm not feeling my best, then it becomes mental and I have to fight, and you have to fight and fight and fight. Today I just I didn't conquer it mentally. I have to be there mentally more than the next player."

The winner of the Radwanska-Bartoli evening match will take on either former world No. 1 Caroline Wozniacki or four-time grand slam winner Maria Sharapova, who meet in Thursday's opening semifinal.

Meanwhile, two-time Miami champion Kim Clijsters is facing four weeks out after injuring her right hip during her third-round defeat to fellow Belgian Yanina Wickmayer.

"The current prognosis is that Kim will have to recover for four weeks first," read a statement on the four-time grand slam winner's website. " As soon as she has returned to Belgium, she will have additional tests."

The 28-year-old is aiming to return at the Madrid Masters in May ahead of the season's second grand slam event, the French Open.