Serena Williams upset by Roberta Vinci in US Open semis

Story by ESPN
Written by Greg Garber

NEW YORK -- Two match wins away from tennis history, Serena Williams finally failed in a major moment Friday.

Unseeded Italian Roberta Vinci stunned the No. 1-ranked player 2-6, 6-4, 6-4 in the US Open semifinals for one of the greatest upsets the sport has ever seen. It was Williams' first loss in a Grand Slam singles match this year and ended her bid for the first calendar-year Slam since 1988.

Vinci ended Williams' 2015 major streak at 26 straight matches and, going back to last year's US Open, 33 overall.

Read more: http://espn.go.com/tennis/usopen15/story/_/id/13631724/serena-williams-pursuit-calendar-year-grand-slam-ends-us-open-semifinals