After a wild week in Montreal and Toronto, who knows what will happen in Cincinnati.
Rafael Nadal, Roger Federer and Andy Murray failed to reach the quarterfinals in the men's event, while Wimbledon champion Petra Kvitova, French Open winner Li Na, Wimbledon runner-up Maria Sharapova and world No. 1 Caroline Wozniacki were all bounced prior to the last eight in the women's tourney. True.
Surely order will be restored in Ohio, the final substantial tune-up before the U.S. Open. Or will it?
Here's a breakdown of the draws.
First quarter: Nole versus the rest
The way he's been playing, the biggest obstacle for Djokovic in Cincinnati could be the heat. He'll likely begin Wednesday, when temperatures are expected to hit around 90 degrees.
His opponent might be the talented, fearless and brash 19-year-old Ryan Harrison. Will Harrison be giving Djokovic any advice after saying Federer needed a little more fire against the elite? Doubt it.
Such is Djokovic's form and return game that even a dangerous floater like John Isner wouldn't hurt the Serb should they battle in the third round.
Another American, Andy Roddick, surfaces in Djokovic's quarter. Roddick makes his U.S. Open Series debut in 2011 following yet more injuries and has a tough opener, versus a former conqueror, Philipp Kohlschreiber.
Second quarter: Fed versus Delpo
Del Potro needed to bypass only one round this time to get to Federer in Cincinnati, and he did that when first-round opponent Andreas Seppi retired Sunday trailing 4-1.
What a match it figures to be. Del Potro has won their past two head-to-heads, including an outstanding 2009 U.S. Open final, and winning three in a row wouldn't help Federer's confidence heading into Flushing Meadows. Both were faring better back then.
Del Potro was expected to raise his game during the U.S. Open Series, his most productive stretch of the campaign, but he also lost earlier than planned in Los Angeles.
Third quarter: Murray's return?
Murray won the Rogers Cup the previous two years but then didn't do as well as expected at the ensuing U.S. Opens. Perhaps losing his opener in Montreal, then, was a blessing in disguise.
On reputation and past performance, Murray's potential second-round match against David Nalbandian is a heavyweight bout. But Nalbandian isn't close to peak form, working his way back from several serious injuries.
The more serious threat is surging Frenchman Jo-Wilfried Tsonga, coming off semifinal showings at Wimbledon and the Rogers Cup, downing Federer both times. It remains to be seen, though, how Tsonga recovers from the bicep injury that forced him to retire against Djokovic in Montreal.
Fourth quarter: Rafa's reply
For those wondering if Djokovic's recent mastery of Nadal would throw the Spaniard off against others, we got the answer in Montreal. Nadal lacked belief against Ivan Dodig in the second round, unable to put away the Croatian when given numerous opportunities.
As such, even when presented with a tame looking draw in Cincinnati, Nadal may still be vulnerable. And his possible first opponent, fellow Spaniard Guillermo Garcia Lopez, has beaten him before.
The form player in the quarter is easily Mardy Fish, doing a commendable job as the U.S. men's No. 1. Fish finally ended his Canadian slump to reach a third straight final this summer, and given that he's twice a runner-up in Cincinnati, it could be four in succession.
Semifinal predictions: Djokovic def. Federer, Murray def. Fish
First quarter: Tricky for Woz
They might lock horns in the third round, although Vinci, playing the best tennis of her career at the age of 28, has to navigate past the ever-dangerous Nadia Petrova in the first round. Wozniacki, meanwhile, won't have it easy in her opener, confronting either American Christina McHale, already a solid competitor, or enigmatic Bulgarian Tsvetana Pironkova.
How Kvitova would love to get another crack at Andrea Petkovic, too. Kvitova's flat groundstrokes went astray against the consistent Petkovic in windy conditions in Toronto, and the result was a 6-1, 6-2 drubbing.
Second quarter: Early test for Vika
It was mostly a good week for Victoria Azarenka in Toronto. She put an upset loss against Marina Erakovic at the Bank of the West Classic behind her and progressed to the semifinals. However, once there, Azarenka was overmatched by Williams. Their previous encounters at the Australian Open suggested a closer score was on the cards.
Azarenka needs to be sharp straightaway in Cincinnati since she's likely to play one of the tour's hottest players, Sabine Lisicki, in the second round. Owner of that mammoth serve, Lisicki has gone 17-3 in her past 20 matches.
Agnieszka Radwanska is as hot -- winning nine of her past 10 -- although the Pole doesn't possess Lisicki's immense power. Lisicki edged Radwanska when they clashed in Stanford.
Third quarter: Serena versus Sam, again
Williams and Samantha Stosur played for the Rogers Cup title on Sunday. They won't be meeting in the final in Cincinnati. Rather, the draw means Williams and Stosur are likely second-round combatants.
Her motivation has been questioned in the past, but Williams appears to have more hunger than ever, and at this point, she must be the overwhelming favorite in New York.
Early in the U.S. Open Series, Sharapova said she would look forward to playing Williams soon. She got her wish in Stanford, and the outcome was horrendous for the Russian. Would the result be any different if they tangled in the quarterfinals?
Wimbledon and the French Open were good tournaments for Sharapova, but getting pummeled by Williams and then losing to a qualifier in Toronto in the third round, Galina Voskoboeva, set her back.
Fourth quarter: Bartoli's recovery
Marion Bartoli said she couldn't do anything right after losing to Voskoboeva in Toronto. The unforced errors flew off her racket. An open quarter means Bartoli, who had excelled since late in the clay-court season, could get back on track in Cincinnati.
There's also an opportunity for second-seed (yes, she remains that high) Vera Zvonareva. Zvonareva will be happy not to see Radwanska anywhere around her, outdone by Radwanska at her prior two tournaments in Toronto and Carlsbad.
By the looks of it, Anastasia Pavlyuchenkova, one of the purest ball strikers around, hasn't recovered after blowing a hefty lead in the French Open quarterfinals to Francesca Schiavone. This is an important week for the 20-year-old.
Semifinal predictions: Lisicki def. Kvitova, Williams def. Bartoli
London-based Ravi Ubha covers soccer and tennis for ESPN.com. You can follow him on Twitter.