For nearly 50 minutes they traded strokes, the young American hopeful and veteran Frenchwoman, neither able to take command of the quarterfinal clash of contrasting styles.

Then came the first sprinkles of rain. It wasn’t enough to halt play in the view of spectators. But it was enough to give Marion Bartoli pause, given the number of players who had fallen on Wimbledon’s grass the previous week.

Her opponent, 20-year-oldSloane Stephens, the last American remaining in Wimbledon’s singles draw, was in the midst of a must-hold service game, trailing 5-4 in the first set, the score knotted at 40-all, with a place in the semifinals at stake.

And from that moment on, Stephens’s Wimbledon campaign took an unfortunate turn. The momentum shifted dramatically following the suspension of play that Bartoli lobbied for and got after gesturing toward the court as if it were an oil-slick hazard.

When play resumed 90 minutes later, Stephens’s serve deserted her, enabling Bartoli, whose own serve was shaky as well, to polish off the first set, break Stephens five times in the second set and advance with a 6-4, 7-5 victory.

If Stephens had an opinion about whether play should have been halted at such a crucial juncture, it was impossible to tell. Though it was just her second Wimbledon appearance, she carried herself with remarkable poise, not flustered in the slightest by the smattering of raindrops or Bartoli’s anguished expression as she called for the Grand Slam supervisor.

Asked afterward whether she considered it gamesmanship on Bartoli’s part, Stephens said simply, “I don’t know. Who knows?”

The crowed clearly felt it was, jeering and whistling at Bartoli and cheering Stephens roundly when play resumed.

Of far greater import to Stephens was that she learn from the experience, put the disappointment behind her and continue working hard.

“I’m not going to dwell on it,” said Stephens, who’s scheduled to compete in Washington’s CitiOpen later this month. “I forget things easily. I think that’s a good thing.”

Bartoli, Wimbledon’s 2007 runner-up, has neither the classic physique nor conventional strokes of a professional tennis player. But she’s effective, able to rip sharply angled, crosscourt shots with her two-fisted forehand and backhand. She’s reasonably fleet afoot as well, which helps compensate for the reach she surrenders with her two-handed shots.

With the tournament’s top three seeds swept from contention, this Wimbledon offers a golden opportunity for women who have labored in the shadow of Serena Williams, Victoria Azarenka and Maria Sharapova.

Bartoli was one of two to reach Tuesday’s quarterfinals without losing a set. Belgium’s Kirsten Flipkens was the other, and both advanced. Flipkens upset 2011 champion Petra Kvitova, 4-6, 6-3, 6-4, to earn a semifinal meeting with Bartoli.

Germany’s Sabine Lisicki, who toppled Williams the previous round, breezed past Kaia Kanepi, 6-3, 6-3, to earn a meeting with her former junior rival, fourth-seeded Agnieszka Radwanska, who turned back Li Na, 7-6 (7-5), 4-6, 6-2.