One minute you're doing algebra, the next minute you're beating the World No.5 - it was all in a day's work for Madison Keys as the first round of the Mutua Madrid Open continued Sunday.
WTA Staff

MADRID, Spain - When the Mutua Madrid Open draw came out, all eyes were on the top quarter, where both Williams sisters, Li Na and Caroline Wozniacki were all lurking - but that's all over now, as only one of those four WTA greats were left standing after first round play continued on Sunday.

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The No.10-seeded Wozniacki was the first to fall, losing out to Yaroslava Shvedova, 62 64. Shvedova originally looked headed for a smoother win as she led 62 31 - Wozniacki clawed back into the second set with three straight games, but Shvedova closed it out with three straight games of her own.

"I played well in Fed Cup and Stuttgart so I came onto the court today feeling good, even though I knew Caroline was the favorite," Shvedova said. "I was just focusing on what I needed to do today. In the end I was a bit nervous but I managed to close it out anyway, so I'm very happy about it."

There's another reason Shvedova thinks she is playing well in Madrid. "I play well on the Roland Garros surface, and since they put the Roland Garros clay here, I'm playing well again!" she said. "I hope they will put this Roland Garros clay on more tournaments so I can win some more matches."

Shvedova got her fifth Top 10 win, after wins over Jelena Jankovic (2009 US Open), Agnieszka Radwanska (2010 French Open), Li (2012 French Open) and Sara Errani (2012 Wimbledon).

In another upset, American teenager Madison Keys, who lost in the final round of qualifying on Saturday but made it into the main draw as a lucky loser, pulled off a 63 62 shocker against the No.5-seeded Li, throwing down five aces en route to the first Top 10 win of her very young career.

"I didn't think I'd be in, so I just sat around and waited all day, then 10 minutes before the match I got a text message telling me I was going on and to get ready!" Keys said. "I was on the couch doing homework when I got the text message. It was algebra. It helped I had no idea I was going to play, so I didn't overthink it. And then I was so excited, and then the adrenaline came, and I went out.

"I just kind of started playing, and it felt really good, and I was able to win. It feels great."

Elsewhere, Venus Williams was forced to withdraw from the tournament due to a low back injury.

So Serena Williams had a lot to gain by winning her match and she sure did, rallying from 3-1 down in a tight 61-minute first set but then rolling against Kazakh qualifier Yulia Putintseva, 76(5) 61.

"Yulia and I train sometimes at the same facility, the Mouratoglou Academy in France - I see her around a lot and see her working really hard," Williams said. "Honestly, I obviously have to - and want to - play better as each match goes on here. I felt a little sluggish out there today, but I'm happy I won."

The No.1-seeded Williams, who won her first clay court tournament of the year on green clay in Charleston, was asked about her prep for the European clay court season, which is all on red clay.

"I've been in Europe for a little over a week; maybe a week and a half. Not super long, but not long enough. I was training in Paris for a few days and I just came to Madrid a couple days early."

The other Top 10 players in action all won through, though it wasn't easy by any means: No.4 seed Agnieszka Radwanska rallied from 3-1 down in the second set to beat Tsvetana Pironkova, 62 64; No.6 seed Angelique Kerber rallied from a set and a break down to beat Hsieh Su-Wei, 36 63 62; and No.8 seed Petra Kvitova came back from 4-2 down in the third to beat Yanina Wickmayer, 46 75 64.

The other six seeds in action went 5-1, with No.11 seed Nadia Petrova, No.13 seed Maria Kirilenko, No.14 seed Marion Bartoli, No.15 seed Dominika Cibulkova and No.16 seed Ana Ivanovic moving on, but No.12 seed Roberta Vinci falling in a see-saw three-setter to Varvara Lepchenko at night, 61 16 62.

Ekaterina Makarova, Sorana Cirstea, Kaia Kanepi, Svetlana Kuznetsova, Chanelle Scheepers, Anabel Medina Garrigues and María-Teresa Torró-Flor also won through as first round action continued.