LONDON — For the first time in more than a century, no American singles players reached the round of 16 at Wimbledon.

The last two of 23 U.S. entrants departed Monday. First, Madison Keys withdrew because of a strained left thigh before her third-round match that was suspended because of darkness on Saturday was supposed to resume. Then, No. 9 John Isner lost his third-round match despite hitting 52 aces, eliminated 6-7 (8), 7-6 (6), 7-6 (3), 7-5 by 19th-seeded Feliciano Lopez of Spain.

Not since 1911 had zero U.S. men or women been in the round of 16 at Wimbledon, according to the International Tennis Federation. That year, no American women even entered the tournament and only three men did.