Kim Clijsters defeated Serena Williams 6-4 7-5 in the US Open semi-final on hard. The upset overturned the form book — Serena Williams came in leading the head-to-head 7–1, defending the title. Kim Clijsters narrowed the head-to-head to 7–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2003-03-19 | Miami | SF | hard | Serena Williams | 6-4 6-2 |
| 2003-01-13 | Australian Open | SF | hard | Serena Williams | 4-6 6-3 7-5 |
| 2002-11-06 | WTA Tour Championships | F | carpet | Kim Clijsters | 7-5 6-3 |
| 2002-09-16 | Tokyo | F | hard | Serena Williams | 2-6 6-3 6-3 |
| 2001-03-21 | Miami | R16 | hard | Serena Williams | 6-0 6-2 |
| 2001-03-08 | Indian Wells | F | hard | Serena Williams | 4-6 6-4 6-2 |
| 2000-03-10 | Indian Wells | R16 | hard | Serena Williams | 6-4 6-4 |
| 1999-08-30 | US Open | R32 | hard | Serena Williams | 4-6 6-2 7-5 |
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About
Averages over each player's completed matches in the selected window (111 vs 199). ATP, WTA & Challenger.
Performance in the biggest moments — break points, deciding sets and tiebreaks (0–100, higher is better). About