US Open Tennis 2013 Results: Analyzing Sunday's Most Impressive Early Winners

The true contenders in both the men's and women's draw for the 2013 U.S. Open are beginning to separate themselves from the rest of the field, and several of their standout performances highlighted Sunday's early action.

Both defending champions were the headliners. Serena Williams faced Sloane Stephens, who had defeated her in the Australian Open quarterfinals earlier in the year on hard courts. But Williams managed to blow past her after a difficult opening set.

Meanwhile, No. 3 seed Andy Murray encountered more difficulty but continued on to the Round of 16.

Let's take a closer look at the prowess that was on display from Williams, Murray and the other impressive winners in the early matches on Day 7.

Note: Statistics and information are courtesy of USOpen.org.

No. 1 Serena Williams: 6-4, 6-1 over No. 15 Sloane Stephens

The battle of powerful American women was lopsided, unlike their last Grand Slam encounter in which the precocious Stephens prevailed.

It was a different story this time around. While Williams didn't have her best tennis in the beginning, Stephens sealed her fate with 21 unforced errors in the opening set alone.

Williams was threatened in opening the second set on serve at deuce but managed to overcome that and break Stephens to go up 3-1, from which her younger, less experienced counterpart couldn't recover.

Lack of consistency continues to plague Stephens, who hits the ball with comparable velocity to Williams and is in magnificent shape to get to almost any ball. However, she's still far from being ready to take home the Grand Slam hardware.

This was Williams' most difficult hurdle before the semifinals, where she'll encounter a top-10 player and possibly one as good as third-seeded Agnieszka Radwanska.

Based on how Williams handled this showdown, expect her to be back in the final and likely to win this tournament for the second year in a row.

No. 3 Andy Murray: 7-6 (2), 6-2, 6-2 over Florian Mayer

Another player named Mayer gave Murray trouble after Leonardo Mayer had taken a set off the 2012 tournament winner in Round 2.

However, Murray promptly righted the ship once Florian Mayer pushed him to a first-set tiebreaker, imposing his will and dominating the extra points by a score of 7-2.

A frustrated Mayer smashed a ball against the court at Flushing Meadows in the midst of that stretch, sensing the match was slipping away. He was right, because Murray was locked in and proceeded to dominate.

The third set was particularly impressive, as the Scot struck 15 winners to just three unforced errors.

Murray had surprising losses to Ernests Gulbis in Montreal and Tomas Berdych in Cincinnati preceding the year's final Grand Slam event. Now he enters the Round of 16 in New York seemingly revitalized and in top form.

 

No. 5 Tomas Berdych: 6-0, 6-2, 6-3 over No. 31 Julien Benneteau

The player who last beat Murray couldn't get past Rafael Nadal in the semifinals of the Western & Southern Open, but Berdych nevertheless has used that momentum to his advantage at the U.S. Open thus far.

Berdych took it to the seeded Julien Benneteau, overpowering the Frenchman with 11 aces and an array of groundstrokes that allowed him to capitalize on six of 14 break-point chances.

A hard-fought, straight-sets win over Denis Kudla in the previous match prepared Berdych well, as he hit 36 winners and only 14 errors on Sunday.

Round 4 promises to be more challenging for Berdych as he faces ninth-seeded Stanislas Wawrinka, who needed four grueling sets to knock off Marcos Baghdatis in his most recent match.

The virtuosity on display from Berdych indicates that he should be able to advance to the quarterfinals, where a marquee showdown with Murray likely awaits.

 

No. 18 Carla Suarez Navarro: 4-6, 6-3, 7-6 (3) over No. 8 Angelique Kerber

The upstart 24-year-old is becoming more of a factor on the Grand Slam stage, and thanks to her rally from a set down against Angelique Kerber, Carla Suarez Navarro is deeper than she's ever been at the U.S. Open.

Chris Goldsmith pointed out the impressive rise Suarez Navarro has had lately in major events overall:

Unfortunately, the road from here is tough, with Williams lined up as her next opponent. But the Spanish star known for her one-handed backhand has certainly held her own thus far.

Although Suarez Navarro doesn't hit the ball particularly hard, she is precise with her placement—especially with her serve. In each of her four matches, she's averaged in the high 70s and peaked as high as 82 in first-serve percentage.

What may be the undoing of Suarez Navarro is her relatively lackluster winners-to-unforced errors ratio, because she's hit more errors than winners in every match of the tournament.