Serena Williams vs. Bethanie Mattek-Sands: Score and Reaction from 2015 US Open

Serena Williams battled back after dropping her first set against Bethanie Mattek-Sands in the third round of the U.S. Open on Friday night at Arthur Ashe Stadium in New York. It was the first time since 2001 that Williams has won a match at the U.S. Open after losing the first set.    

Her pursuit of a calendar sweep of the Grand Slams stayed on track as well as she looks to become the first player since Steffi Graf in 1988 to win all four majors in the same calendar year.

It was not until the third set that she began to play like the Williams who has won three Grand Slam titles in 2015 as she had to overcome 28 unforced errors. Here is a look at the score from Friday night:

Player	Set 1	Set 2	Set 3
Serena Williams	3	7	6
Bethanie Mattek-Sands	6	5	0

The closer Williams progresses toward playing for a Grand Slam sweep, the more the pressure builds. And it seems that the third rounds of majors have provided her with some trouble, according to ESPN Stats & Info:

That didn't change Friday night.

Mattek-Sands, who was part of this year's winning doubles side at the Australian Open, started well, especially near the net. She has been able to hone her drop shots, picking the right times to approach the net. 

Williams, on the other hand, struggled to find her rhythm and couldn't maintain any sort of rally. Eight minutes into the match, she was down 3-0 in the first set.

Comedian Sean Kent couldn't believe what he was seeing:

But it looked as though nerves were getting to Williams. She had difficulties finding her footwork, which contributed to her 14 unforced errors in the first set.

Williams won two straight sets at the end, but Mattek-Sands took the first set 6-3. She matched Williams shot for shot, which had the world No. 1 hanging her head at times. It was the first time an American has won a set against Williams at the U.S. Open since her sister Venus did so in 2005. 

For Matt Cronin of TennisReporters.com, Mattek-Sands' first-set win heated things up:

Dropping the initial set in a match doesn't necessarily doom Williams. She came into the day with an 11-1 record this year when losing set No. 1, usually showing incredible resiliency.

But Mattek-Sands did not roll over. After Williams jumped out to a 5-3 lead in the second set, the challenger stormed back to tie it at five games apiece. Williams' serve helped her win the set as she was finally able to shift some momentum her way and gain a 7-5 victory.

U.S. Open Tennis shared the replay of Williams' winner:

When she's trailing, tennis fans can often see a very animated Williams as she tries to build herself up. After taking a point in the second set, you could tell she was ready to win it. US Open Tennis posted video of Williams sliding into the splits:

Mattek-Sands left the court before the third set, causing a short delay, but whatever she went inside to address, it didn't help.

Williams hit her stride in the final set and proved to be unstoppable, shutting out Mattek-Sands 6-0. The quick turnaround enthralled ESPN's Chris Fowler:

Friday's winner spoke of her slow start and triumphant turnaround with USA Today's Ava Wallace:

"

I’m not trying to live on the edge. I’m playing players that come out really strong. I don’t think I came out too slow, I just think Bethanie played really well, I had to do things and adapt to her game. I was finally able to get some rhythm going toward the end of the second.

"

Mattek-Sands won just five points in the third set, but there is no questioning that this was her finest performance on a major stage. Williams' mental fortitude proved to be too much Friday night. She'll face another American in Madison Keys in the fourth round, with Williams needing four more wins to make history.

Follow Joe Pantorno (@JoePantorno) on Twitter.

Stats courtesy of USOpen.org.