Serena Williams vs. Elina Svitolina: Score and Reaction from 2016 Olympics

Serena Williams is shockingly done at the Rio Olympics, losing to Elina Svitolina in round-of-16 play on Tuesday, 6-4, 6-3.

The top player in the world, who has already been eliminated from the doubles competition along with her sister, Venus Williams, was the defending gold medalist in the singles tournament and had won gold in 2000, 2008 and 2012 in the doubles tournament, making her elimination altogether on Tuesday all the more baffling.

Jon Wertheim of Sports Illustrated didn't see this result coming:

Indeed, it wasn't Williams' finest moment, per Rick Bonnell of the Charlotte Observer:

“Obviously I’m disappointed,” Williams told Dan Wolken of USA Today. “The better player won. It was a great opportunity that didn’t work out the way I wanted it to. At least I was able to make Rio, which was one of my goals. It was awesome, but it’s over now.”

It was a humble response, but Williams also looked less than 100 percent, as Chris McKendry of ESPN noted:

Take nothing away from Svitolina, however.

She won 79 percent of her first-serve points, had only 17 unforced errors and double-faulted just twice. She managed the match well, allowing Williams the opportunity to defeat herself.

And beat herself she did. For every positive on the afternoon, the negatives were more pronounced. She had five aces but eight double-faults. She had 26 winners but 37 unforced errors. She won 71 percent of her first-serve points but just 29 percent of her second-serve points.

Williams had beaten Svitolina in their previous four matches.

“It was just an unreal feeling, just a relief for me because I didn’t expect even in that moment that I could win,” Svitolina told Wolken. “And I think it helped me a lot—you don’t expect mistakes from her and just fight and stay focused."

With the loss, both top seeds in the men's and women's tournaments, Novak Djokovic and Williams, have now been eliminated. But the repercussions of this match may be felt well beyond Rio, as Wertheim hinted:

While Williams will now turn to preparations for the U.S. Open, assuming she's healthy enough to play, Svitolina will have another tough task awaiting her in the quarterfinals against the hard-hitting Petra Kvitova on Wednesday.

The 11th-seeded Kvitova is inconsistent, however. If the 15th-seeded Svitolina executes a similar plan as she did Tuesday against Williams, she'll be a tough out for Kvitova.

All stats via NBCOlympics.com. You can follow Timothy Rapp on Twitter.