Patrick McEnroe defeated Jan Siemerink 6-4 6-4 in the Hong Kong round of 16 on hard. The upset overturned the form book — Jan Siemerink came in defending last year's quarter-final. Patrick McEnroe extended the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-08-19 | Long Island | R32 | hard | Patrick McEnroe | 4-6 6-4 6-3 |
| 1990-10-15 | Vienna | R32 | hard | Jan Siemerink | 4-6 7-5 6-3 |
Averages over each player's completed matches in the selected window (16 vs 199). ATP, WTA & Challenger.
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About