So who can still stop the first Grand Slam in 27 years?
Only three candidates remain at the United States Open, four if you count Serena Williams, who has been known — though not lately — to be her own biggest tennis enemy.
But Williams, who is now just two victories away from a Grand Slam, has shown nothing but resilience under mounting pressure throughout this tour de force of a season.
Odds are, it will require something resembling the match of a lifetime to take her out at this late stage of the game.