Who could have expected this?
Going into Sunday, not even Juan Martin del Potro, his career ravaged by wrist injuries, thought he could summon the kind of consistent, forceful tennis capable of tossing Novak Djokovic from the Rio Olympics' singles draw. Del Potro admitted as much after playing one of the best matches of his career under a dark evening sky: "I didn't expect to win," the Argentine said after his raucous 7-6 (4), 7-6(2), upset over Djokovic, the world's top-ranked male player by a wide margin.
This was a match significant on many levels.
It showed that del Potro -- one of tennis' great talents and winner of the 2009 US Open -- was rounding into form after spending the past several years largely watching from the sidelines.
It showed that Djokovic, far and away the best player in men's tennis since 2011, is maybe, just maybe, losing a little firmness on his solid grip over the game.
And for Andy Murray, the upset led to a simple revelation: Suddenly devoid of his most potent nemesis -- a man who the irrepressible Brit has lost to in 16 of their past 19 matches -- this tournament is now his to lose.
Sunday evening's turn of events was unforgettable. While Djokovic had suffered an ugly upset early at Wimbledon, losing to American journeyman Sam Querrey, it seemed like he'd built back confidence by winning the Toronto tour stop in late July. But from the beginning of this Olympic match he seemed the lesser player. Del Potro served solidly, kept his backhand in play and absolutely dominated with his favorite shot: a forehand that he consistently poleaxed with such power that his opponent, among the game's best-ever movers, was constantly wrong-footed.
In the end, del Potro hit 29 forehand winners. Djokovic struck seven. The final point featured a sequence symbolized the whole affair: Del Potro hit a scorching forehand down the line and drew a weak reply. The lanky Argentine then wheeled back and hit nearly the same shot, only this time crosscourt. It struck the net, but was traveling with so much heavy force that it popped onto his opponent's side. Game. Set. Match. New tournament.
The crowd, which had sung and clapped and danced all night in a way that made Centre Court feel like a stadium hosting soccer's World Cup, once again went apoplectic. Del Potro and Djokovic -- who played a similarly stirring match for the bronze medal in London, with the Argentinian winning then too -- embraced at net. As Djokovic left the court, his face flashed with a look of agonized disappointment and he appeared to be crying.
One can reliably assume that Murray, the singles medal winner at the 2012 London games, wasn't shedding any teams. He survived the day, easing through a 6-3, 6-2 win over Serbia's Viktor Troicki on a wind-swept afternoon. There are no unnerving threats in his half of the draw. The highest seeded is France's Gael Monfils, ranked 11th on the ATP tour. Murray has won four of their six matches, and the talented Frenchman has a penchant for crumbling on the biggest stages.
With Djokovic out of the way, the Olympic draw's upper half is now led by Rafael Nadal, who on Sunday tore through Argentina's Frederico Delbonis, 6-2, 6-1. But Nadal of late has been a shadow of his former self. Nursing an injured wrist, he hasn't played a tournament since June. It's not too much to say that if Del Potro continues showing the form he did against Djokovic, he may well offer Murray his sternest test.
After his match against Troicki, Murray admitted to being nervous before his match began -- less because this was the Olympics than the fact he hadn't played competitively since winning Wimbledon on July 10, hadn't performed at a hard court tournament since losing early at the Miami Open in March.
"Having the Olympics come so soon after Wimbledon for me, it may have been easy to have a bit of a lull, but that's not going to happen with the Olympics," Murray said. "I hope to make a run."
Little did he know that by Sunday's end, Novak Djokovic would be gone. That run just got a whole lot easier.