Serena Williams (x1) bt Maria Sharapova (x5) 6-4, 6-1.

The three most decorated players from Melbourne in the Open era all won in straight sets Tuesday, with Williams starting the roll with a 6-4, 6-1 win over 2008 champion Sharapova in a rematch of last year's final.

"It was super intense".

"She was making a lot of great shots". Is she can frustrate Serena by absorbing the American's power game - something she's yet to figure out - and wait for errors to creep into her opponent's play, there is a definite chance for her.

Sharapova came into the tournament light on match practice after injuring her left forearm and said getting that treated would be her main priority on her return home. "Yeah", Sharapova added in the same report.

Radwanska didn't even have a game point until the first game of the second set, which she won to get on the board.

Sharapova served a career-best 21 aces against Belinda Bencic in the previous round but failed to penetrate Williams, who broke twice in each set.

"She presents a completely different game, an extremely exciting game", Williams said of the wily Pole. "I just feel like I'm playing the best I can and I can't believe I'm in the final!" a breathless 21-time Grand Slam champion told Rennae Stubbs during her on-court interview. "Hopefully not. Unless you know something I don't know", she said when asked if this could be her last Australian Open.

At 4-4, Radwanska airmailed a forehand long at break point, giving Williams a lead she would not relinquish. But Williams soon dominated the third game and broke to quickly level at 2-2.

Despite the American, who was forced to pull out of the Hopman Cup earlier this month due to a knee injury, calling for the doctor between the sets, she pulled away from Sharapova to seal a straight sets 6-4, 6-1 win.

Williams won that game, then the set, then the first five games of the second set.

First in action on Thursday are world number one Serena Williams and fourth seed Agnieszka Radwanska.

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

"I'm just going to watch the final".

She used different words to describe how it felt to continuously fall short against Williams: frustrating, inspiring, motivating... but her face reflected one emotion - disappointment. Asked what the secret was to her longevity, she replied: "I honestly have no idea". "I mean, I think I would be a real princess if I was complaining". Despite her momentous win against Sharapova again, she has nothing but good things to say about her opponent.

Her grip on the title looks unlikely to be threatened in the semi-finals by Agnieszka Radwanska, who has lost all eight of her matches against Williams.

"I've been playing this week aggressive and I didn't start that way so after the first set I just wanted to play the way that got me to the quarter finals".