Australian Open: Novak Djokovic sets up Roger Federer date as Serena Williams dismantles Maria Sharapova

Serena Williams set up a semi-final against Agnieszka Radwanska.

Melbourne: Serena Williams beat Maria Sharapova for an 18th straight time despite a bout of food poisoning Tuesday to set up an Australian Open semi-final against Agnieszka Radwanska, who has never won against the dominant American.

Novak Djokovic hammered an off-key Kei Nishikori and Roger Federer put on a masterclass against Tomas Berdych as they set up a dream semi-final at the Australian Open on Tuesday.

Defending champion Djokovic recovered strongly from his five-set struggle against Gilles Simon as he ousted Nishikori 6-3, 6-2, 6-4, after Federer swept aside Berdych 7-6 (7/4), 6-2, 6-4.

Serena Williams heaped more misery on her long-time rival 6-4, 6-1, with the Russian fifth seed stretching her demoralising winless run against the American great to 12 years.

With Sharapova again swatted aside, the 34-year-old world number one, gunning to match Steffi Graf's Open-era Grand Slam record of 22 titles, now has the composed Pole in her sights.

The signs are not good for Radwanska, despite her convincing 6-1, 6-3 win over Spanish 10th seed Carla Suarez on Rod Laver Arena.

While her record against Williams is not yet on the scale of Sharapova, it is still dismal. They have played eight times since 2008 Agnieszka has lost the lot, taking just one set along the way.

It meant the five-time Grand Slam winner's demoralising jinx against Williams remains intact, dating back to 2004 when she last beat her in the Wimbledon final.

Despite yet another defeat, Sharapova tried to take away some positives.

"It's motivating because she's at a different level. She makes you go back to the drawing board, not just for me, but for many other players," she said.

"She makes you work. That's inspiring." 

Meanwhile, Djokovic is seeking his 11th Grand Slam title while Federer, 34, is looking to extend his record tally to 18 -- and both will want to take charge of their head-to-head, which is locked at 22-22.

"Any round (against Federer) feels like a final because of the fact that we are, you know, big rivals, we played so many times against each other," Djokovic said.

"There's a lot of tension. There's a lot at stake. I'm expecting a great fight in two days.

Both players will have a close eye on Wednesday's quarter-finals pitting Andy Murray against David Ferrer and Milos Raonic against Gael Monfils.

Djokovic will start as favourite against Federer after he beat him in the Wimbledon and US Open finals last year on his way to winning three Grand Slam titles and finishing runner-up at the French Open.

The Serb made 100 unforced errors and was pushed all the way in Sunday's five-set struggle with Simon, but he said a day away from tennis had done him the world of good.

"I didn't practice yesterday. I didn't hit a tennis ball," he said. "It happens sometimes, it's actually good to rest your mind, rest your body. Less is more sometimes."

- 'It means a lot' -

Thursday's semi-final promises to be a test of Djokovic's continued dominance of men's tennis, after his achievement in losing only one Grand Slam match last season.

In a sign of the pair's hold on men's tennis, Federer is into his 39th Grand Slam semi-final while Djokovic has 29.

They were both on court for little over two hours on Tuesday.

Djokovic only hit 11 groundstroke winners in disposing of Nishikori, who made a total of 54 unforced errors and had his service broken six times.

"I think today was more (about) my game. I was missing too much, especially first couple sets. Lost many easy games," said Nishikori, who was also troubled by a leg injury.

"I couldn't make him work hard today. I mean, yes, he played good. But I couldn't play good tennis today."

Earlier Federer reached his 12th Australian Open semi-final in 13 years with a clinical straight-sets win over Berdych in two hours, 16 minutes.

The Swiss has high hopes he can add a fifth Australian Open title, even though his last Grand Slam success was back at Wimbledon in 2012.

"It means a lot. It's part of the reason why I'm still playing," Federer said. "I feel like I'm competitive at the top. I can beat all the guys on tour.

"It's nice now that in the last three Slams that I've been as consistent as I have been."

Federer said he was enjoying his tennis after adding former world number three Ivan Ljubicic to his coaching team, along with long-time mentor Severin Luthi.

"I'm playing good tennis, fun tennis for me anyway. I really enjoy being able to come to the net more like back in the day.

"So I'm very pleased. It would mean a lot to me (to win more Slams), no doubt about it."

The world number three had few concerns against the strong-serving Berdych and extended his career record to 16-6 to deny the Czech a third straight semi-final appearance in Melbourne.