Serena Williams had done all the heavy lifting, or so it seemed.
She conquered the grass of Wimbledon, the red clay of Roland Garros, the hard courts of the Australian Open.
All that was left for tennis' first Grand Slam since 1988 was a victory in the U.S. Open, surely a mere formality when Williams got to the semifinals with a 43rd-ranked Italian standing in her way.
At 33, Williams was poised to put a remarkable capper on a brilliant career.
Roberta Vinci had other ideas.
"Every so often," Vinci said, "a miracle happens."
For Williams, it was a nightmare. After cruising through the first set 6-2, she finally seemed to feel the weight of history. Her legs got sluggish, her shots spraying all over the court. Vinci evened the match 6-4, and took the decisive third set by the same score.
"I saw she was nervous," Vinci said, "and that helped me."
Williams' loss will surely go down as one of the biggest upsets in any sport, which was the only way to stand apart in 2015.
Several of these jaw-droppers would've been at the top of the list just about any other year:
DOWN GOES ROUSEY! Ronda Rousey was supposed to be invincible. She won her first 12 mixed martial arts fights — eight of them in less than a minute — before stepping into the cage against Holly Holm in Melbourne, Australia. Rowdy Ronda finally met her match Down Under, when Holm finished her off with a devastating kick to the head. "I'll be back," Rousey vowed.
PERFECT SEASON CRUMBLES: With a roster full of NBA-quality underclassmen, Kentucky was 38-0 and needed two wins to become the first undefeated men's hoops team in nearly four decades. Turns out, the Wildcats weren't perfect after all. Hard-nosed Wisconsin took down John Calipari's squad 71-64 at the Final Four. "The season was a waste," Kentucky's Tyler Ulis said.
THE BRAVE BLOSSOMS: In rugby, there's a clear line between the world's top teams and everyone else. South Africa belongs in the first group. Japan is undoubtedly part of the second. But on the game's biggest stage, the team known as "The Brave Blossoms" pulled off the greatest upset the sport has ever seen, beating the two-time Rugby World Cup champion Springboks 34-32. "I'm glad we've managed to not only surprise our own fans back in Japan," fullback Ayumu Goromaru said, "but also fans across the world."
ONE SHOT TOO MANY: Jordan Spieth won the first two major championships on the golfing calendar, and coming down the stretch of the British Open it looked as though he'd make it three in a row. The young Texan shared the lead with two holes to go after sinking a 50-foot birdie putt. But he missed an 8-footer at the 17th and slipped out of a playoff by a single shot, denied in his bid for the first modern Grand Slam. "We gave it a great effort," Spieth said.
GRAVEYARD OF CHAMPIONS: It was certainly a glorious year for American Pharoah, which became the first horse in 37 years to capture the Triple Crown. But even he was bitten by the upset bug at Saratoga, a track appropriately known as the "Graveyard of Champions." Caught in the stretch by 16-1 long shot Keen Ice, American Pharoah lost the Travers by three-quarters of a length. But he'll always have that Triple Crown.
THE MOUSE THAT ROARED: Bournemouth was toiling in the fourth level of English football in 2010. After climbing to the Premier League for the first time, the Cherries pulled off stunners in back-to-back games this season, knocking off defending champion Chelsea and 20-time champion Manchester United. "Just checking the results again to make certain the last week has actually happened," chairman Jeff Mostyn tweeted afterward.
FATHER AND SON: We'll all remember Kentucky's loss, but perhaps the most compelling image from the NCAA tournament was injured Georgia State coach Ron Hunter tumbling off his stool after his son R.J. hit a 3-pointer to cap an improbable upset by the 14th-seeded Panthers over No. 3 Baylor. And let's not forget UAB prevailing against Iowa State in another 14-beats-3 shocker.
KICK SIX: Georgia Tech went 1-7 in the Atlantic Coast Conference this season. That lone win won't soon be forgotten. Lance Austin returned a blocked field goal 78 yards for a touchdown on the final play to give the Yellow Jackets a 22-16 victory Florida State, snapping the Seminoles' 28-game ACC winning streak. Also worthy of mention from college football: Michigan State ending Ohio State's bid for a second straight national championship, and Texas handing Oklahoma its only loss in the Red River Showdown.
IT'S ALL IN THE NAME: Tyson Fury was born to be a fighter, even though he entered the world three months early weighing just one pound. His father predicted the ailing infant would not only survive, but grow into a heavyweight champion. Doubling down, he named his son after Mike Tyson. That prophecy was fulfilled when Fury, now 6-foot-9, scored a unanimous decision over Wladimir Klitschko, ending his 9 1/2-year reign as champion.
If it was any consolation to Klitschko, he had plenty of company in 2015.