Nadia Petrova defeated Maria Sharapova 6-1 6-2 in the WTA Tour Championships round robin on carpet. The upset overturned the form book — Maria Sharapova came in leading the head-to-head 9–0, defending the title. Nadia Petrova claimed a first win over Maria Sharapova in ten meetings, narrowing the head-to-head to 9–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2012-08-27 | US Open | R16 | hard | Maria Sharapova | 6-1 4-6 6-4 |
| 2009-08-17 | Toronto | R64 | hard | Maria Sharapova | 6-3 6-4 |
| 2009-07-27 | Stanford | R16 | hard | Maria Sharapova | 6-1 6-2 |
| 2009-05-25 | Roland Garros | R64 | clay | Maria Sharapova | 6-2 1-6 8-6 |
| 2006-10-23 | Linz | F | hard | Maria Sharapova | 7-5 6-2 |
| 2006-01-16 | Australian Open | QF | hard | Maria Sharapova | 7-6(6) 6-4 |
| 2005-08-29 | US Open | QF | hard | Maria Sharapova | 7-5 4-6 6-4 |
| 2005-06-20 | Wimbledon | QF | grass | Maria Sharapova | 7-6(6) 6-3 |
| 2003-08-04 | Los Angeles | R32 | hard | Maria Sharapova | 6-2 2-6 7-5 |
Averages from each player's recent completed matches (20 vs 19). ATP, WTA & Challenger.