(AP) Roberta Vinci has stunned Serena Williams to end her Grand Slam bid in one of the greatest upsets in tennis history.

The 43rd-ranked Italian won 2-6, 6-4, 6-4 in the U.S. Open semifinals Friday.

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Vinci had never won a set off the 21-time major champion in four previous meetings and was in her first career Grand Slam semifinal at age 32.

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So tense she was guiding in overheads, Williams became more and more frustrated by Vinci’s defense and creative shot-making in the final two sets. She had won in three sets 11 times in majors this year in her pursuit of the first Grand Slam since Steffi Graf in 1988, but was unable to dig out of this hole.

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