LONDON (AP) — The stunning string of upsets at Wimbledon continues into the second week. Defending champion Serena Williams lost in the fourth round, falling 6-2, 1-6, 6-4 to Sabine Lisicki (lih-SIH'-kee) of Germany.

The loss ended Williams' career-best 34-match winning streak and her attempt to capture a sixth title at the All England Club.

Williams was up a break twice in the third set but Lisicki fought back both times and broke again to go ahead. She converted her second match point with a forehand winner.

Sloane Stephens is the lone American still in singles contention after her fourth round win over Monica Puig (PWEEG). Former champ Petra Kvitova (kuh-VIHT'-oh-vuh), fourth seed Agnieszka Radwanska (ahg-nee-ESH'-kuh rahd-VAHN'-skuh) and Li Na (lee nah) are among the others to reach the women's quarterfinals.

In men's play, Andy Murray keeps alive his hopes of becoming the first British man to win Wimbledon since Fred Perry in 1936. The second-seeded Murray reached the quarterfinals for the sixth straight year, beating Mikhail Youzhny 6-4, 7-6, 6-1. Top-seed Novak Djokovic (NOH'-vak JOH'-kuh-vich) topped Tommy Haas 6-1, 6-4, 7-6 to make it into the final eight. Fourth-seeded David Ferrer (feh-REHR') and No. 8 seed Juan Martin del Potro (wahn mar-TEEN' dehl POHT'-roh) also scored fourth round wins.