LONDON — This most unpredictable of Wimbledons delivered yet another surprise Friday when reigning Australian Open champion Madison Keys, the No. 6 seed, was a lopsided loser in the third round, eliminated 6-3, 6-3 by 104th-ranked Laura Siegemund of Germany.

The men’s field has also seen its share of surprises, including a Wimbledon record 13 seeds going out in the first round. “At times, it wasn’t the best quality, let’s say. But I managed, and in the end,