This was thrown into sharp relief this weekend at the U.S. Open. On Saturday, Roger Federer had a gilded opportunity to make still more history, brandishing two match points -- on his serve! -- against Novak Djokovic. Done in by Djokovic's bold shotmaking and his own nerves, Federer couldn't close the deal and lost 7-5 in the fifth set of the semifinal. Both Federer and Djokovic essentially distilled the match to the same principle: Hey, that's sports.
On Sunday, on the same court in Arthur Ashe Stadium, the example was even more vivid. Australia's Sam Stosur stared down the mighty Serena Williams -- surpassing her not only in power and athleticism but also in competitive will and poise -- and, improbably, won the women's final 6-2, 6-3 to claim the first major of her career.
A quick scan of the scoreline would suggest that the match wasn't close. A scan of the seedings would suggest that Stosur (No. 9) should have beaten Serena (No. 28). Yet make no mistake: This ranks among the most seismic upsets in recent tennis history.
Williams entered the final with an 18-0 record on hardcourts this summer, including six victories at the U.S. Open, where she hadn't dropped set. She looked poised to win her fourth Open title and her 14th in Grand Slam events.
Before Sunday, Stosur was known principally for her solid physique and shaky head. Perhaps the best pure athlete in the women's game, she is -- er, was -- also known as something of a head case. Last year she showed off her athleticism and power, reaching the finals of the French Open. She lost a winnable match to Francesca Schiavone and then beat a hasty retreat. As recently as this summer at Wimbledon, she was a first-round loser.
But at the U.S. Open, she managed to marry her mind and body, matching her shotmaking with self-belief. In the third round, she outlasted Nadia Petrova in the longest women's match in tournament history. In the fourth, she lost the longest women's tiebreak in Grand Slam history, then rallied to win the third set and advance past Maria Kirilenko. In the semifinals against unseeded Angelique Kerber, she dropped the second set but again collected herself and prevailed.
In the final, she played the biggest match of her life like it was just that. Relentlessly aggressive, unshakably poised, a look of all business pinned to her face, she "out Serena-ed" Serena. In the match's most tense moments, it was Stosur who met them head on.
"I can't actually believe that I've won this tournament," Stosur told reporters at her post-match news conference. "To go in there and play the way I did is obviously an unbelievable feeling. You always want to be able to do that, but to actually do it is unbelievable.
"It I was going to win, I didn't think I'd be able to do it in 6-2, 6-3, that's for sure. After that first set, I could feel my heart pounding out of my chest."
The second set brought a different kind of emotion. In the first game of the set, Stosur had two break points on Serena's serve. The former world No. 1 was able to fight off the first and appeared to have a winner on the second, prompting a roaring "Come on!" before Stosur was able to get part of her racket on the ball. Chair umpire Eva Asderaki ruled "intentional hindrance" against Williams, resulting in a point penalty that gave Stosur the game.
"If you ever see me walking down the hall, look the other way, because you're out of control," Williams said to Asderaki during the next changeover. "You're out of control. You're totally out of control. You're a hater. You're unattractive inside. Who would do such a thing? And I never complain. Wow."
But before the headlines predominately lead with another Serena outburst (as they inevitably will), it's worth pointing out that Stosur was poised before and after Williams' tirade.
"That was probably the loudest I've ever felt a crowd in my whole entire life," Stosur said of the fans' response to Williams' point penalty. "And you're right in the middle of it. It was definitely quite an overwhelming feeling. But once I hit that next ball in the court and started playing again, I felt settled."
Stosur proved it by winning the final three games of the match. After pasting one last forehand winner on match point, Stosur dropped to the court. She then rose to leap into the stands and hug her support team. The match was over and now Stosur, too, couldn't quite believe what had just transpired. It was a reminder that, in sports, anything can happen. It was reminder why we watch.