Ondruska grew up as a child of Czechoslovak parents in South Africa. In 1989 he became a professional tennis player and won his first Challenger tournament that same year in Durban . In the following year he was also able to win a first challenger tournament in doubles. In 1992 he was in the final of an ATP tournament for the first time , at the only one time held Cologne Open in Cologne he was defeated by Bernd Karbacher in two sets, and on his way to the semi-finals of the Miami Masters in 1993 he defeated Michael Chang and Michael Stich . Overall, he was in the final of an ATP tournament three times, but could not win any. In doubles he was significantly more successful, in 1996 alone he won three tournaments alongside alternating partners, his last victory he celebrated in Long Island , which he won together with David Prinosil . He reached his highest ranking in the tennis world rankings in 1993 with position 27 in singles 34 in doubles.
His best individual result in a Grand Slam tournament was reaching the round of 16 at the Australian Open in 1996. In the doubles competition, he reached the semi-finals of the Australian Open in 1993 on the side of John-Laffnie de Jager .
Ondruska played 21 singles and one doubles game for the South African Davis Cup team between 1993 and 2001 . In 1995 and 1996 he was with his team in the quarter-finals of the world group, both lost 4-1. He could only win one of his four singles, against the Italian Renzo Furlan . In general, his record was positive, his only appearance in doubles he won alongside Wayne Ferreira , his individual record was 12-9. At the 1996 Summer Olympics , he went to South Africa and was eliminated in the second round against Christian Ruud , having previously won against Goran Ivanišević .
South Africa