Playing career
Sonnekus finished his schooling in Welkom and studied at the University of the Free State. He played his first provincial match for the Free State in 1974 and continued to represent the union until 1985. During his career with the Free State he played in five Currie Cup finals, being on the losing side in 1975, 1977, 1978 and 1981. In 1976 he was a member of the Free State team that won the Currie Cup final against Western Province and gained is winners medal when he went on as a replacement for Eben Jansen during the match.[2] With his retirement at the end of the 1985 season, Sonnekus was the Free State record holder for most matches of 160, most matches as captain of 63, most tries of 69 and most Currie Cup matches of 104.[3]
Sonnekus played three test matches for the Springboks. His first test was the third tests in the series against the 1974 Lions team captained by Willie John McBride, played at the Boet Erasmus Stadium in Port Elizabeth, when he was selected as scrumhalf. His second test match was almost ten years later, once again at the Boet Erasmus Stadium, this time as number 8 against England. He then played in the second test against the English, at Ellis Park and scores his first test try during the match.[4]
Test history
| No. | Opposition | Result (SA 1st) | Position | Tries | Date | Venue |
|---|---|---|---|---|---|---|
| 1. |  British Lions |
9–26 | Scrumhalf | 13 July 1974 | Boet Erasmus Stadium, Port Elizabeth | |
| 2. |  England |
33–15 | Number 8 | 2 June 1984 | Boet Erasmus Stadium, Port Elizabeth | |
| 3. | England |
35–9 | Number 8 | 1 | 9 June 1984 | Ellis Park Stadium, Johannesburg |