Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Race Name | Circuit | Date | Winning driver | Constructor | Report |
| --- | --- | --- | --- | --- | --- |
| XIV Argentine Grand Prix | Buenos Aires | 24 January | Chris Amon | Matra | Report |
| VI Race of Champions | Brands Hatch | 21 March | Clay Regazzoni | Ferrari | Report |
| Questor Grand Prix | Ontario Motor Speedway | 28 March | Mario Andretti | Ferrari | Report |
| XII Spring Trophy | Oulton Park | 9 April | Pedro Rodriguez | BRM | Report |
| XXIII BRDC International Trophy | Silverstone | 8 May | Graham Hill | Brabham - Cosworth | Report |
| VI Rhein-Pokalrennen | Hockenheim | 13 June | Jacky Ickx | Ferrari | Report |
| XVIII International Gold Cup | Oulton Park | 22 August | John Surtees | Surtees - Cosworth | Report |
Question:
What circuit did Clay Regazzoni win?
Answer:
Brands Hatch