MELBOURNE - Agnieszka Radwanska has won her way through to her second Australian Open semi-final on Tuesday, but will have Serena Williams to contend with after the world No 1 also breezed through the quarterfinal stage of the tournament.

The No 4 seed Radwanska was relentless in her 6-1, 6-3 win, brushing aside No 10 seed Carla Suarez Navarro in just one hour and 22 minutes on center court.

Radwanska, who incidentally lost to Williams in her only Grand Slam final berth back in 2012, said her focus was now on making her first Australian Open final.

She said her victory at the end-of-year WTA tournament in Singapore last year has filled her with confidence heading into matches with top players such as Williams.

"In hindsight, that win (against top players) give me more confidence," she told the press.

"But this is a new season, new Grand Slam; you're starting over again."

Following Radwanska's straightforward victory, Williams was just as clinical in her 6-4, 6-1 win over No 5 seed Maria Sharapova.

In what was the pair's 21st meeting on the tour, Sharapova took an early 2-0 lead in the match, but was unable to consolidate; the world No 1 battled strongly to regain parity and then run away with a hard-fought, hour-long first set.

Williams then found another gear, easily closing out the match 6-1. The American said despite having won the previous 17 matches against Sharapova, the 18th straight win was full of fight, and the scoreline wasn't indicative of the struggle on court.

"It was super intense. She is an incredibly intense, focused player," Williams said of Sharapova post-match.

"When you're playing someone like that you have to come out with your own fire and intensity."

Sharapova admitted she was unable to capitalize on her early break of serve in the first set, and said Williams was simply too good in the second.

"I thought she played explosively," Sharapova said in her press conference.

"She played a really good second set, returned well and really got me on the back foot."

The world No 1 Williams, who hasn't played Radwanska since 2013, said the 4th seeded Pole was a significant roadblock on her chase for a seventh Australian Open title.

"(Radwanska) is a great defender and I think it will be a great match. I'm going to do my best, I have nothing to lose," Williams said on Tuesday.

The pair will face off in their semi-final in Melbourne on Thursday.