1. Roberta Vinci Upset Victory Over Serena Williams
Going into the 2015 Grand Slam semifinal matchup pitting superstar Serena Williams against journey-woman Roberta Vinci, the world was captivated by Williams, who was on a 33-match Grand Slam winning streak. After already winning the first three major tournaments at the Australian Open, French Open and Wimbledon, the #1 ranked Women’s Tennis player was poised to etch her name in history with no clear competitors in her way.
Prior to the match, many sports books did not even offer odds of #43 ranked Roberta Vinci winning. Playing in her first ever Grand Slam semifinal and Serena in her 47th, the Italian tennis player was clearly out matched. Yet, Vinci shocked the world as she was able to defeat Williams in sets, making this one of the biggest upsets in sports history.