US Open Tennis 2012: Biggest Upsets so Far at Flushing Meadows

Despite the tournament only being a few days old, already the 2012 US Open has provided us with results and upsets that we simply didn't see coming.

We always expect the likes of Serena Williams and Roger Federer to cruise through the opening rounds of the competition, and while those two in particular faced no problems, several other high-profile stars weren't so fortunate.

Read on to see the biggest upset from both the men's and the women's competition so far at the 2012 US Open.

Guillermo Garcia-Lopez def. Juan Monaco (10)

Guillermo Garcia-Lopez's victory over Juan Monaco was one of the more improbable wins that any tennis fan has seen in recent years at Flushing Meadows.

Not only was the Spaniard playing a much more experienced and superior opponent, he lost the opening two sets 6-3, 6-1 and looked to be completely out of the match. He only landed 52 percent of his first serves for the match, only won 35 percent of his receiving points and hit an incredible 75 unforced errors.

Yet somehow, and I say somehow, Garcia-Lopez prevailed in a five-set thriller, which saw the Spaniard clinch the final two sets in tiebreakers.

Incredible for Garcia Lopez; heartbreaking for Monaco.

Irina-Camelia Begu def. Caroline Wozniaki (8)

Irina-Camelia Begu faced off against former World No. 1 Caroline Wozniaki in the opening round of the 2012 US Open and simply put, wasn't expected to put up too much of a fight. Wozniaki has never won a Grand Slam, but she was meant to be too strong and too powerful for her opponent.

Oh how wrong we all were!

Begu simply blew Wozniaki off the court—taking just over an hour to pick up a straight sets victory over her more fancied rival. 

Her serve was never broken and she won over half of Wozniaki's own service points en route to a stunning 6-2, 6-2 victory that would move her through to the second round of the competition.

Which was the bigger upset of the two results?

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