Head to head
1
Hard
1
1
Clay
1
2
Carpet
1
John Alexander's wins on the left · Jaime Fillol Sr.'s on the right · bar lengths share one scale
Momentum
Running lead across all meetings, oldest to newest (walkovers excluded).
All meetings (7)
| 1981 | Mexico City | Clay | R16 | Jaime Fillol Sr. | 7-6 4-6 6-1 |
| 1975 | Las Vegas | Hard | QF | John Alexander | 6-3 7-6 |
| 1973 | Brussels WCT | Carpet | R16 | John Alexander | 5-7 7-6(5) 6-3 |
| 1973 | St. Louis WCT | Carpet | R16 | John Alexander | 6-4 7-6(4) |
| 1973 | Toronto WCT | Carpet | R16 | Jaime Fillol Sr. | 6-3 6-7(3) 6-4 |
| 1969 | Charlotte | Clay | R16 | John Alexander | 6-4 7-9 6-4 |
| 1969 | San Juan | Hard | R32 | Jaime Fillol Sr. | 6-0 8-6 |
Methodology
Head-to-head totals and surface splits exclude walkovers (no match was played), which follows ATP convention — walkover meetings still appear in the match list. The momentum chart plots the running lead across all counted meetings, oldest to newest.