U.S. Open Day 12 - Ladies' day

NEW YORK – Serena Williams was overly excited once she reached the U.S. Open quarter-finals.

Understandably so, if a tad dramatic in the grand scheme of things. But it was the first time the world No. 1 had reached the final eight at a major this season.

Now that she's in the final four, she's back in familiar territory – particularly at the U.S. Open, where she is the two-time defending champion. And when Williams looks at the three other remaining women in the singles draw – her friend Caroline Wozniacki, No. 17 seed Ekaterina Makarova and unseeded Shuai Peng – and realizes that the title doesn't go through anyone currently in the top 10, well, it's a golden opportunity to right her Slam ship for 2014.

Not that we'll hand the trophy to her on Friday; anything can happen – and has. Just look at Williams's season, and at the upsets that have occurred in this tournament for the aforementioned three to still be alive on the second Friday. They have 24 WTA Tour titles amongst them; all but two of them belong to Wozniacki.

Here's how the two women's semi-finals shape up.

[1] Serena Williams vs. [17] Ekaterina Makarova

Williams is by far the most rested of the final four. She has dropped just 22 games in getting to the semifinals and has spent the least time on court (six hours, 45 minutes).

The two have played four times, with Williams winning three of them without dropping a set. The lone exception was the Australian Open in 2012; Makarova won their fourth-round match 6-2, 6-3.

Makarova's big win to get here was her 7-6, 6-4 victory over No. 7 seed Genie Bouchard in the fourth round. She was also in the right place at the right time; Bouchard was overcome by the extreme conditions, which Makarova handled much better. As well, she faced a diminished Victoria Azarenka in the quarter-finals, after the 2013 finalist fell victim to food poisoning the previous day.

They say you're better off being lucky than good. But the truth also is that Makarova was quite capable on her own of pulling off both victories.

According to the WTA Tour match notes, Williams is 59-9 in her career against lefthanders (23-1 at Grand Slams, with the only defeat the one to Makarova in Australia). This is the third lefty Williams will face in this tournament, after wins over countrywomen Taylor Townsend and Varvara Lepchenko. They are rather different players than Makarova but still, that's good and recent experience.

Williams has lost nine times at the U.S. Open in her career. All but one were to top-10 players with the exception being Kim Clijsters in 2009. Clijsters didn't have a ranking at the time, but you'd have to put a pretty big asterisk on that one.

[10] Caroline Woznacki vs. Shuai Peng

The Danish former No. 1 hasn't had an opportunity this golden to reach a Grand Slam final in a long, long time. So it will be interesting to see how she handles it.

She has won her last five meetings with Peng, her only loss coming in their very first encounter all the way back in 2007, when Wozniacki had just turned 17.

This is the first Grand Slam semi-final for Peng; actually, it was her first career quarter-final, too. So it's all uncharted territory. And nothing in her recent past history against top players presaged her run. Coming into the U.S. Open, Peng had lost her last 10 straight matches against top-20 players.

She defeated two of them on her way to the final four: No. 4 Agnieszka Radwanska and No. 14 Lucie Safarova, who was coming into New York on a very good run this summer.

Peng will be back in the top 20 herself, if she can beat Wozniacki.

It's been an eventful tournament for Peng. For one thing, it was reported that her clothing sponsorship with Li Ning expires at the end of the season, so her timely run in a Slam can't help but improve her lot there. As well, it was announced that she and doubles partner Su-Wei Hsieh of Taipei would be ending their partnership with this event. They lost to Date-Krumm and Zahlavova Strycova in the third round. But the two got to the No. 1 spot in the world together, and are the reigning French Open champions.

What else is going on? Well, the mixed doubles final goes before the two women's singles semis.

That's an event that can produce rather unlikely champions – just a couple of years ago, the young American team of Jack Sock and Melanie Oudin took the title.

This time, the No. 1 seeds, Sania Mirza of India and Bruno Soares of Brazil, are in the final. They will face unseeded American Abigail Spears and partner Santiago Gonzalez of Mexico.

The junior, college invitational and wheelchair events continue, with several American kids still in the hunt in the juniors: Stefan Kozlov and Francis Tiafow in the boys' singles, and Alicia Black, Caroline Dolehide and Katerina Stewart in the Girls' singles. Both events are at the quarterfinal stage.