PARIS — Ana Ivanovic lost in the third round of the French Open, while American teen Sloane Stephens advanced on Friday.

Ivanovic fell to Sara Errani of Italy 1-6, 7-5, 6-3, and Stephens advanced to the fourth round by beating Mathilde Johansson of France 6-3, 6-2.

The 13th-seeded Ivanovic, a former top-ranked player who won the French Open title in 2008, committed 37 of her 40 unforced errors in the final two sets. Errani had only 18.

Of the eight teenagers in this year’s draw, the 19-year-old Stephens was the only one to reach the third round.

Later Friday, top-ranked Novak Djokovic and 2009 champion Roger Federer will play their third-round matches, while second-seeded Maria Sharapova will play in the second round.

The second-seeded Rafael Nadal improved his French Open record to 47-1 on Thursday after beating Denis Istomin of Uzbekistan 6-2, 6-2, 6-0. If he wins five more matches, he will break the record of six French Open titles he shares with Bjorn Borg.

Nadal wasn’t the only record-breaker on court Thursday. John Isner, the American who won the longest match in tennis history two years ago at Wimbledon, lost 18-16 in the fifth set of another marathon match.