It had been billed as the first heavyweight battle of this year's Australian Open, but any boxing referee would surely have intervened well before the end to prevent serious injury.
Sharapova, who now plays Belgium's Kirsten Flipkens, had won her first two matches earlier this week without dropping a game and went 4-0 up before Williams got on the board. The world No 2 has therefore reached the fourth round for the loss of just four games, which is the least any player has dropped en route to the last 16 here since Steffi Graf did the same in 1989.
Since all Grand Slam tournaments went to 128-strong fields, the lowest number of games dropped in the first three rounds was the two Mary Pierce conceded at the French Open in 1994. Caroline Wozniacki lost just three games in reaching the fourth round of the 2010 US Open.
"I was a really determined player out there because I knew the tennis that she's capable of producing," Sharapova said after her 79-minute victory. "Despite what she's ranked or seeded, it doesn't matter when you go out on the court. She's been there."
Williams, who had appeared to be heading for an even heavier defeat when she trailed 5-1 in the second set, said it had been "definitely not my best day". As the American continues to deal with Sjogren's syndrome, which causes fatigue and joint pain, speculation about an impending retirement is likely to grow.
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