Tennis: Djokovic powers into Aussie Open semis

Serbian superman Novak Djokovic remains firmly on course for a third straight Australian Open title after dismantling Tomas Berdych in four sets to set up a last four meeting with Spanish comeback king David Ferrer.

Showing no signs of fatigue from the grinding five-hour duel with Stanislas Wawrinka that ended in the early hours of Monday morning, Djokovic defused the big Czech's big serve 6-1 4-6 6-1 6-4 to progress comfortably to his 11th successive grand slam semi-final.

Maria Sharapova was just as impressive as she continued a ruthless march through the women's draw with a 6-2 6-2 savaging of Ekaterina Makarova, while Li Na ended Agnieszka Radwanska's winning streak to continue her love affair with Melbourne Park.

Ferrer staged what he described as a miraculous comeback from two sets down to beat fellow Spaniard Nicolas Almagro 4-6 4-6 7-5 7-6 6-2 but immediately said he would need something even more spectacular if he was to get to his first grand slam final.

Living up to his reputation as the fittest player on the tour, world number one Djokovic returned with his usual deftness and moved his 6ft 5in (1.96m) opponent around the court.

The 25-year-old whipped through the first set against fifth seed Berdych quicksmart, stalled only a little as he lost the second before racing to victory in two and a half hours, sealing the win with his 10th ace.

"It was a great performance," Djokovic said. "I was hoping to have a shorter match and not go over five hours like the last match.

"It is always going to be tough against Tomas ... but I came out and played my best tennis."

Sharapova crushed fellow Russian Makarova in just 66 minutes to set up a last four appointment with Li at a cost of just nine games conceded in the tournament, a record low for the Australian Open.

The second seed and 2008 champion relentlessly pummelled Makarova with a barrage of thumping serves and fierce forehands, leaving the 19th seed scrapping for dignity by the end.

"She's playing unbelievable, so aggressive, and just in the right spot of the court. It's really tough to play against her now," said Makarova.

MIRACLE VICTORY

"In the end I just was fighting for the games, because I was thinking that, yeah, it's tough to beat her."

Ferrer stared defeat full in the face three times before taming Almagro after being dominated by some brilliant tennis from the 10th seed for the first two sets.

The fourth seed looked to be heading for the exit when he faced Almagro serving for the match at 5-4 in the third set but he hustled along the baseline to claw his way back into the contest.

Twice more Almagro had chances to serve out for victory but he blew them both before suffering a leg injury and Ferrer, who had won all 12 of their previous meetings, emerged a winner after three hours and 44 minutes.

Ferrer, 30, has lost all four of his previous grand slam semi-finals, including defeats to world number one Djokovic at the U.S. Open in 2007 and last year.

"It was a miracle I won this match," said Ferrer. "I tried to fight and do my best but next round I need to play my best tennis, better than today," he said.

"Nole is a special player."

Li reached her third semi-final in four years at the Australian Open with a 7-5 6-3 victory over Radwanska in the opening match of the day.

Radwanska had come into the contest bursting with confidence on a run of 13 successive wins but looked underpowered as she was bludgeoned into submission by Li in the 102-minute contest.

There were 10 service breaks in the 21 games and sixth seed Li grabbed six of them to set up a contest against Sharapova, who won all three of their encounters last year.

The former French Open champion clearly likes the bright blue courts at Melbourne Park, even if she will probably need to get her unforced error count under the 40 mark if she wants to reach a second final after 2011.

"I really don't know what it is here," Li said. "It seems whenever I come down here my results are always quite consistent, no big setbacks or anything.

"I'm not sure whether it's the winter training but it does seem like I'm just better at this tournament."

Radwanska, who had not lost a set on her way to the quarter-finals, said it was possible that she had paid the price for playing and winning warm-up events in Auckland and Sydney.

The Pole also thought Li had a good chance against Sharapova.

"I think it's 50/50, to be honest," she said. "They're both playing very well tennis this week, definitely. For sure it's going to be good match."