MELBOURNE, Australia — Andy Murray overcame an inconsistent serve to beat Kei Nishikori on Wednesday and reach the semifinals of the Australian Open for the third straight year.
The No. 4-ranked Murray won 6-3, 6-3, 6-1 to join No. 2 Rafael Nadal and No. 3 Roger Federer in the semifinals. Top-ranked Novak Djokovic had a chance to complete a powerful final four later with a win over David Ferrer of Spain.
Nishikori, the first Japanese man to reach the quarterfinals here in the Open era, showed flashes of the form that earned him a surprise win over former finalist Jo-Wilfried Tsonga in the previous round.
During the first set, Nishikori played a lob shot through his legs on his way to winning the point — but by that time he was already a break down.
Murray, who hasn't dropped a set since the first round, broke seven times in all, although he plans to work on his serve after only managing a 44 percent success rate with his first serve.
"The returning was good, so that was positive," said Murray, who lost in the Australian Open final the last two years. "Could have served better, that's for sure."
Murray will face either Djokovic, who beat him in last year's final, or Ferrer on Friday. Federer and Nadal will meet for the 27th time in the other semifinal, scheduled for Thursday.
The women's semifinal matchups were completed Wednesday when former and reigning Wimbledon winners Maria Sharapova and Petra Kvitova both won in straight sets.
After Kvitova beat unseeded Italian Sara Errani 6-4, 6-4, Sharapova set up a repeat of last year's final at the All England Club with a 6-2, 6-3 defeat of fellow Russian Ekaterina Makarova.
Kvitova beat Sharapova 6-3, 6-4 in their last Grand Slam meeting to claim her first major 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.
To earn the No. 1 ranking, Sharapova must repeat her 2008 Australian Open title. 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.
"It's been a long road back to this stage," said Sharapova, sidelined for 10 months with a shoulder injury that required surgery.
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 other women's semifinal will feature defending champion Clijsters against third-seeded Azarenka. Those matches will be played Thursday along with the highly anticipated match between Federer and Nadal, who have 26 Grand Slam titles between them.
Federer beat 2009 U.S. Open champion Juan Martin del Potro 6-4, 6-3, 6-2 Tuesday 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.
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.
Thursday's match will be the first time Federer and Nadal have met at Melbourne Park since the Spaniard won the 2009 title in five seesawing sets. Nadal collected the trophy from the great Rod Laver after consoling Federer as he sobbed in the background.
"We are talking about a player who has won 16 Grand Slams, and I've won 10," Nadal said. "We have played a lot of matches together, many in very important moments for our careers. So the matches against him are always special, even if we are (ranked) 20 against 25."