ESTORIL, Portugal - A day after No.1 seed Alisa Kleybanova stormed through her opener at the Estoril Open, No.2 seed and birthday girl Jarmila Gajdosova did the same, winning nine straight games from 3-4 in the first set to beat 95th-ranked Renata Voracova over on Centralito, 64 60.

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Gajdosova, ranked No.31 and celebrating her 24th birthday, cracked the match open midway through the first set with some hard hitting, firing eight aces in the match and cracking winners off both wings. The second set took 27 minutes.

The other seeds had mixed results. No.3 seed Klara Zakopalova fought from 1-4 in the second set to beat Spanish qualifier Beatriz García Vidagany, 64 76(3), while No.8 seed Greta Arn was also tested, going to three sets to get past Portuguese wildcard Maria Joao Koehler, 62 36 63. But No.4 seed and defending champion Anastasija Sevastova wasn't so fortunate, serving for the match at 75 65 but ultimately falling to Urszula Radwanska, 57 76(5) 61.

"I really like it here, it's a nice tournament, but I didn't play so well today," a disappointed Sevastova commented. "It's my mistake, it's my problem."

Anabel Medina Garrigues, Kristina Barrois and Anastasiya Yakimova also won as the first round wrapped up at the International-level tournament.

Also among the winners was Sloane Stephens, who beat fellow American teenager Melanie Oudin, 62 61. Stephens, who turned 18 a month ago, had cruised through the qualifying draw too, losing just 13 games in three rounds.

"It was kind of upsetting two Americans had to play, but Melanie's such a great player and a really good friend of mine, and one of us had to win," Stephens said. "Last week I was in Fès, Morocco, which was a great tournament, but I lost last round of qualies. I'm happy Estoril has been treating me well!"

This was the fourth time Stephens has won a main draw match in her young career, and Wednesday she will try to reach her very first WTA quarterfinal as she plays Romania's Monica Niculescu. Niculescu beat another American, Bethanie Mattek-Sands, in a three-hour-plus match in the first round.

"Everything's been working pretty well for me here," Stephens said. "Most girls don't really like clay but I love it. I'll just try to get as many balls back as I can.

"I have nowhere to go - I'm going to be in Europe for two months, so I have plenty of time. I can stay out here all day, I don't mind!"