PARIS (AP)—After beating Venus Williams at the French Open, Poland's Urszula Radwanska played a qualifier ranked 127th with the chance to set up a third-round match against her older sister, No. 4-seeded Agnieszka.

She couldn't come through.

After playing so well for three sets, across more than three hours, against seven-time Grand Slam champion Williams, 40th-ranked Urszula failed to put up much resistance during a 6-3, 6-3 loss to Germany's Dinah Pfizenmaier in the second round Wednesday.

Afterward, Urszula insisted she wasn't thinking ahead to a possible all-in-the-family matchup, which would have been the fifth between the Radwanskas on tour - and second at a Grand Slam tournament.

''It wasn't about that,'' Urszula said. ''I didn't think about it at all.''

The 22-year-old Urszula and 24-year-old Agnieszka haven't played one another in more than a year. Agnieszka holds a 3-1 lead.

''It's always not easy to play against a sister,'' Urszula said. ''But not (happening) this time, I guess.''

Urszula began the French Open with a 7-6 (5), 6-7 (4), 6-4 victory Sunday against Williams, who is rather familiar with the concept of on-court sibling rivalry: She and her younger sister Serena have met 24 times in all, with eight all-Williams major finals, including at Roland Garros in 2002.

Thinking back to her tight win against Venus a few days ago, Urszula said: ''I was very happy after that match. And today, for sure, I'm upset about this match.''

What went wrong?

''Everything,'' Urszula said. ''I didn't play good at all, from the beginning to the end. It wasn't my game.''

She lost five of the first six games against Pfizenmaier, who finished with a 33-6 edge in winners in only her third career match at a major tournament.

Urszula has yet to make it past the second round in 13 appearances at Grand Slam tournaments. Agnieszka, meanwhile, was the runner-up to Serena Williams at Wimbledon last year.

Agnieszka held up her end of the bargain for a possible Radwanska vs. Radwanska matchup by defeating Mallory Burdette of the United States 6-3, 6-2 on Wednesday.

But instead, she'll face Pfizenmaier, who doesn't know much about Agnieszka.

''Maybe (I'll) watch some videos or YouTube or ask some players,'' Pfizenmaier said. ''Maybe (she'll play) like her sister.''