Sharapova, Kvitova Set up Aussie Open Semifinal Former and reigning Wimbledon winners Maria Sharapova and Petra Kvitova will meet in the Australian Open semifinals after both won in straight sets on Wednesday. Sharapova won 6-2, 6-3 against fellow Russian Ekaterina Makarova, who knocked out five-time champion Serena Williams in the previous round. Kvitova earlier reached the semifinals at Melbourne Park for the first time with a 6-4, 6-4 win over unseeded Italian Sara Errani. Kvitova beat Sharapova in last year's Wimbledon final to claim her first Grand Slam title. "Obviously it was a tough one at Wimbledon," Sharapova said. She's full of confidence and playing the best tennis right now. I look forward to it. Sharapova and Kvitova also kept alive their chances of claiming the top ranking, which Caroline Wozniacki will vacate on Monday after her quarterfinal loss to Kim Clijsters. The fourth-seeded Sharapova must repeat her 2008 Australian title win. Kvitova only has to match or better the run of Victoria Azarenka, the only other player still in the running this week for the No. 1 spot. Sharapova has dropped one set and lost 21 games en route to her first Australian Open semifinal since she won the 2008 final - the last of her three major titles. Roger Federer of Switzerland signs his autographs for fans after his win over Juan Martin Del Potro of Argentina during their quarterfinal at the Australian Open tennis championship, in Melbourne, Australia, Tuesday, Jan. 24, 2012. (AP Photo/Aaron Favila) Close "It's been a long road back to this stage," said Sharapova, who spent 10 months off court with a shoulder injury that required surgery later in 2008. Kvitova was far from her best against an opponent making her debut in a Grand Slam quarterfinal, and with a 0-24 record against top-10 players. The second-seeded Czech made 44 errors and had to come back from a break down in the second set. "I was a little nervous because I knew that everybody expect it will be easy match," Kvitova said. Probably I had in my head that it's a good draw. The men's semifinal lineup also will be completed Wednesday. Defending champion Novak Djokovic is up against fifth-seeded David Ferrer in the first match of the night session. Two-time finalist Andy Murray faces Kei Nishikori of Japan. Two of the so-called "Big Four," Roger Federer and Rafael Nadal, are already through to a marquee semifinal after winning Wednesday. Federer beat 2009 U.S. Open champion Juan Martin del Potro 6-4, 6-3, 6-2 in his 1,000th tour-level match. Nadal rallied for a 6-7 (5), 7-6 (6), 6-4, 6-3 win over Tomas Berdych. Their match on Thursday will be their 27th in all and 10th at a major, but their first in a Grand Slam semifinal since 2005. Yelling "Vamos," disputing line calls, pumping his arms after winning big points and bounding around like a hyperactive kid, Nadal ripped winner after winner against Berdych in a 4-hour, 16-minute display of pure intimidation. He said he was nervous in the first set - he'd lost in the quarterfinals two straight years - but by the third and fourth sets things had changed. "The character on court, the way to win the points ... the level is very positive, much, much better than the end of the season," he said. Semifinals is fantastic result for me. Federer finished his match with one of his classic, one-handed backhands against Del Potro, one of only two men who have beaten him in a major final. The other is Nadal, who has done it six times.