In a match which involved poor serving and high-quality groundstrokes in equal measure, Williams maintained her hold over Sharapova to set up a final showdown with second seed Victoria Azarenka. (Agencies)
Roger Federer, who like Williams will be chasing an 18th grand slam title at the Australian Open later this month, breezed through to the men's semi-finals with a 6-1 6-1 thumping of Australian Marinko Matosevic.
Williams and Sharapova played down their animosity before the match but there was no eye contact during preliminaries and on a steamy night in Brisbane their body language remained distinctly frosty throughout.
The result was a match with an intensity scarcely seen outside of a grand slam, something Williams feels is of great benefit to her.
"(I) feel like I'm being pushed into the deep end straightaway," she said. "I think it's a good thing.
"In Melbourne if I have to face Maria again I'll know a little bit more what to expect. I really didn't know what to expect on friday."
Williams secured the first of the 10 service breaks in the match in the fourth game and though Sharapova broke straight back, she lost her serve twice more as the American ran out a comfortable first set winner.
IN HER FACE
The Russian responded well to hold a 2-1 lead after three consecutive breaks of serve in the second set, before calling her coach Sven Groeneveld to courtside. His words illustrated the match held far more importance than a normal grand slam warm-up.
"You're letting her know you're in her face," he said, adding that she "must commit" to her serve.
Sharapova did win the ensuing service game, but lost the next one to restore parity.
In the tiebreak Williams' brutal groundstrokes gave her the advantage but consecutive double faults kept her opponent in it and she needed three match points before sealing victory with an ace.
Azarenka secured her place in the final with a see-saw victory over Serbia's Jelena Jankovic 1-6 6-3 6-4.
Top seed Williams feels the match will be a good barometer of where they are ahead of the first grand slam.
"I think it'll be a really good match to see where we both stand as the two most consistent players of the last year and a half," Williams said.
In a match which involved poor serving and high-quality groundstrokes in equal measure, Williams maintained her hold over Sharapova to set up a final showdown with second seed Victoria Azarenka.