Roberta Vinci shocks the world as she defeats Serena Williams 2-6, 6-4, 6-4

In one of the most shocking events in tennis history, 43rd-ranked player, Roberta Vinci upset world No.1 Serena Williams in the US Open 2015 semi-finals 2-6, 6-4, 6-4, ending Serena’s chances of completing a calendar grand slam.

The loss also defers Serena’s tying Steffi Graf’s record of 22 grand slam wins to another date.

Chances are the name Roberta Vinci is not in your memory bank, but going forward she will always be remembered as the player whose play on the court, said not so fast Serena Williams, your date with history breaking records will have to wait.

"I don't want to talk about how disappointing it is for me," Serena Williams began in her mandatory post-match press conference, which was brief. "If you have any other questions, I'm open for that."

Serena insisted that pressure did not aid in her defeat.

"I told you guys I don't feel pressure," she said. "I never felt pressure. I never felt that pressure to win here. I said that from the beginning.

But reporters weren’t buying that explanation.

"I made a couple of tight shots, to be honest, but maybe just about two.

"But that, I think ... in any normal match you make two tight shots. Other than that, I don't think I was that tight."

Many fans are saying if it wasn’t pressure, then perhaps, lack of focus was the issue since Serena was seen with former and rumored to be back on-again boyfriend, hip-hop artist Drake.

Oddly enough, with both the No. 1 and No. 2 seeded women out in the semi-finals, this tournament could go down as one of the strangest in US OPEN history.

Italian Flavia Pennetta upset second-ranked Romanian Simona Halep 6-3, 6-1 in Friday's first women's semifinal.

So, Saturday will be an historic match, but not what fans were willing to pay $280 per ticket to watch. It will be the first US OPEN women’s final between two Italian players since the OPEN era began in 1968, and with two women over 30-years-old.

If there is any consolation for Serena Williams fans, Serena still shares the Open era record of six US Open titles with Chris Evert and she receives a check in the amount of $410,975 USD.