Serena Williams crushed Meghann Shaughnessy 6-2, 6-2 on Wednesday to advance to the Australian Open semi-finals for the first time.

The world number one demolished her fellow American in just 65 minutes to show why she is the favourite to win the one major championship that has eluded her.

"I'm definitely thrilled to be in the semi-finals, it will be a lot of fun, so I'm really excited," Williams said.

The 21-year-old will play fourth seed Kim Clijsters in Thursday's semi-finals after the Belgian beat Anastasia Myskina 6-2 6-4.

Serena's elder sister Venus meets Clijsters's Fed Cup team mate Justin Henin-Hardenne in the other semi-final, raising the prospect of a fourth consecutive all-Williams grand slam final.

"Kim is a fan favourite and such a nice person. It will be great fun," Serena said. "I always want to be in the finals. If I manage that I'm real happy. I also want the best for my sister."

Serena was forced to miss last year's Australian Open after twisting her ankle playing against Shaughnessy in Sydney but is now bidding to become the fifth woman in history to hold the four grand slam titles at the same time after winning last year's French Open, Wimbledon and US Open championships.

She was nervous and rusty in her opening round match where she dropped the first set to Emilie Loit but has flexed her muscles more and more each time she has been on court.

Her performance against Shaughnessy was easily her best of the tournament so far. She broke Shaughnessy's serve twice in each set but faced just one break point on her own service.

Shaughnessy, who won the Canberra Classic the week before the Open started, failed to find any way past Serena's brute force and powerful game.