Sara Errani defeated Samantha Stosur 6-3 2-6 6-0 in the WTA Championships round robin on hard. The upset overturned the form book — Samantha Stosur came in leading the head-to-head 6–2, defending last year's semi-final. Sara Errani narrowed the head-to-head to 6–3.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2016-04-04 | Charleston | R16 | clay | Sara Errani | 6-4 7-6(5) |
| 2015-08-31 | US Open | R32 | hard | Samantha Stosur | 7-5 2-6 6-1 |
| 2012-05-28 | Roland Garros | SF | clay | Sara Errani | 7-5 1-6 6-3 |
| 2012-05-14 | Rome | R32 | clay | Samantha Stosur | 6-3 7-5 |
| 2011-02-14 | Dubai | R32 | hard | Samantha Stosur | 6-0 6-1 |
| 2010-08-30 | US Open | R32 | hard | Samantha Stosur | 6-2 6-3 |
| 2010-08-23 | New Haven | R16 | hard | Samantha Stosur | 6-1 3-6 7-6(4) |
| 2008-08-11 | Olympics | R64 | hard | Samantha Stosur | 6-3 6-2 |
Averages from each player's recent completed matches (20 vs 20). ATP, WTA & Challenger.