While second-seeded Jelena Jankovic cruised in straight sets and defending champion Venus Williams shook off a poor first set in winning Thursday, Sharapova's fall caught the most attention.
Alla Kudryavtseva, ranked 154th in the world and making her second appearance at Wimbledon, broke Sharapova's serve five times en route to a 6-2, 6-4 victory. Sharapova committed 22 unforced errors and double faulted eight times in making her earliest exit from a Grand Slam event since the 2003 U.S. Open.
Jankovic swept by Carla Suarez Navarro 6-1, 6-3 and advanced to the third round where she'll meet Carolina Wozniacki.
Williams had problems before topping Anne Keothavong for a 7-5, 6-2 victory. Williams needed to overcome six double faults and 26 unforced errors in moving into the third round.
Tamarine Tanasugarn turned in an upset, beating No. 13 Vera Zvonareva, 7-6 (12-10), 4-6, 6-3. Shuai Pend eliminated 26th-seeded Sybille Bammer, 7-6 (9-7), 4-6, 6-3, and Maria Jose Martinez Sanchez knocked off 32nd-seeded Sania Maria, 6-0, 4-6, 9-7.
In matches involving top seeds No. 5 Elena Dementieva rallied to beat Timea Bacsinszky, 4-6, 6-3, 6-3; ninth-seeded Dinara Safina was a 6-3, 6-2 winner over Su-Wei Hsieh; and 16th-seeded Victoria Azarenka advanced with a 6-1, 6-3 pasting of Sorana Cirstea.
Also Thursday, No. 24-seeded Shahar Peer defeated Emilie Loit, 6-3, 6-4; the 31st-seeded Wozniacki beat Aleksandra Wozniak, 6-1, 6-1; and Marina Erakovic topped German Julia Goerges, 6-2, 7-6 (7-5).