Australian-born former tennis champion Bob Hewitt has been convicted in a South African court of rape and sexual assault decades after the alleged assaults.

Judge Bert Bam said he is satisfied the two women, who had accused the veteran tennis player of rape, and a third woman, who had accused him of sexual assault, were telling the truth.

The charges stemmed from events in the 1980s and 1990s, when Hewitt coached the women as young girls. Hewitt, 75, denied all three charges.

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The judge said the striking similarities among the three womens’ testimonies showed that Hewitt’s conduct was calculated.

Bam described the evidence against Hewitt as “overwhelming”, the SAPA news agency reported.

During the trial, his victims said Hewitt assaulted them during private tennis lessons when they were young girls.

“Time did not erase the crimes. A guilty person should not go unpunished. The scales of justice tip against the accused,” Bam said.

One woman testified that Hewitt had told her “rape is enjoyable” as he assaulted her.

Another victim told the court he had touched her inappropriately 34 years ago and forced her to perform a sex act on him when she was 12 and 13.

Hewitt won numerous Grand Slam events during his career in the 1960s and 1970s and was named to the International Tennis Hall of Fame in 1992.

But his name was removed from the hall of fame in 2012, following allegations that he sexually abused girls he coached.

Hewitt was born in Dubbo, NSW, but has spent much of his life in South Africa.