Shock waves rippled through Arthur Ashe Stadium on Friday afternoon.

Playing a semi-final match that was originally scheduled for Thursday night, but delayed by rain, Serena Williams’s superb summer came to a stunning end, two wins shy of completing the first calendar Grand Slam since 1988. Surprise semi-finalist Roberta Vinci prevailed, 2-6, 6-4, 6-4.

Vinci came into the match as a serious underdog. The 32-year-old Italian had not played a top-10 seed in the fortnight, and had never beaten Williams – or even taken a set – in four previous meetings. A doubles specialist, this was her first grand slam singles' semi-final. Even she hadn't thought she had a shot, she told the crowd after the match. 

Her expectations seemed to be accurate as Williams dominated the first set. Vinci earned an early break to lead 2-1, but Williams took the break right back, then smashed a huge winner to force break point at 3-2. She quickly converted, then converted again at 5-2 to take the set.  

Williams faltered slightly to open the second set, double faulting to let Vinci build a 0-40 advantage, but battled all the way back to hold serve. It looked like she was in control. And the fans were completely in her corner. 

Williams had said earlier in the week that she isn’t accustomed to being the fan favorite in New York, that the crowd usually likes to cheer on the underdog. But on Friday, everyone wanted to see a piece of history. The entire stadium celebrated her winners. They gasped when Vinci broke her to go up in the second set, then sounded pained when Vinci, against all odds, forced a third set. 

It was the second match in a row that Williams took the first set and dropped the second. It was the 12th time this year that she’s had to play a third set. Vinci celebrated that set as though she’d won the match. But it’s nearly impossible to maintain momentum against Williams. She held to open the set, then broke with a massive forehand slam to go up 2-0. She was four games from moving on.

But Vinci refused to cave, fighting back from 40-30 to break Williams. A huge break, followed by a quick hold. Williams looked flat as she failed to take a point off Vinci’s serve. Was she starting to let the weight of the moment get to her? She was four games from advancing to the final, where she'd have attempted to complete the first calendar Grand Slam since 1988, to tie Steffi Graf with most major wins in the Open Era, to pass Chris Evert with most U.S. Open wins. 

Vinci took the first point off Williams’ serve in the next game. The crowd went ballistic when Williams evened it at 15-15, then went to 30-15. She crouched and screamed throughout that game, bellowing as she got to 40-15. Here was the ferocious fighter everyone had come to see. She held. 

In her next service game, Williams built a 40-30 lead, but an error at the net kept the game going. She answered her own mistake with a 126mph ace. The next point produced the best rally this tournament has seen. Williams nearly landed in the photographer’s pit as she attempted to reach the final shot. Back to deuce, then Vinci took the advantage, then held. The Italian was playing superb tennis. She led 4-3. 

At the changeover, the stadium DJ played his Williams rallying cry: “Let it go.” Williams came out and forced a quick break point, but failed to convert. Vinci double faulted on her first game point, giving Williams a chance to stay in it. Williams failed to take the opportunity, though. Vinci held two points later. She led 5-3.

Williams would have to hold, then break to keep her summer alive. She quickly accomplished the first half. But with history on the line, Vinci's serve was just too good. She held with five straight points. Game. Set. Match. There will be no calendar Grand Slam this year.  

As the players shook hands at the net, Vinci told Williams she was sorry. She apologized to the crowd, too. 

“This is an incredible moment for me. It’s like a dream. I’m in the final. I beat Serena," she said on court after the win. "For me it is an amazing moment. I lost the first set, tried to save every single point. I tried not to think about the match, about Serena. It is the best moment of my life. I’m sorry for the American people, for Serena, for the grand slam. But today’s my day. Sorry guys.”

Vinci will face fellow Italian Flavia Pennetta in Saturday's final. Pennetta bulldozed No. 2 Simona Halep earlier Friday, 6-1, 6-3. 

(Yahoo News)