The tourists dominated the start of the three-Test series, reaching 331 for five at the close with Matthew Hayden scoring 122 and Mark Waugh 53.

Fast bowler Donald, 35, collapsed in a heap after a delivery to Adam Gilchrist late in the final session, and had to be helped from the field in tears as he clutched his hamstring.

"It's difficult to asses the damage at this stage. He'll undergo an ultrasound later this evening.

"But you could probably assume from the way he went down that he probably won't play again in this Test."

Donald has made it clear that he wants to retire from Test cricket after this series, but he was clearly disappointed at having to leave the field supported by Smith.

"He's upset. He's been plagued by injury the last year or so," said Smith.

"But perhaps there's a need to now acknowledge that he's been a superstar in South African cricket and put his body on the line so many times.

"He's often played through pain, and it's heart-wrenching to see him tumble to the ground in the way he did."

Donald joined a growing injury list, which already included captain Shaun Pollock and batsman Justin Ontong, ruled out before the match began.

Opening batsman Gary Kirsten was hit in the face fielding at silly mid-on as Mark Waugh attempted to hook a delivery from Andre Nel.

But Smith said Kirsten suffered only a small laceration under his right eye and should be fine to take the field on Saturday.

Tarnished century

Meanwhile the Australian team management have asked local police to charge a spectator who was arrested for spitting at Steve Waugh as the Australian captain left the field following his dismissal for 32.

Two other spectators were arrested at the close of the first day's play for throwing beer at Australian batsmen Damien Martyn and Gilchrist.

A United Cricket Board spokeswoman Bronwyn Wilkinson confirmed: "A complaint was laid, and (one spectator) has been charged with crimen injuria criminal insult.

"At the end of play, two more spectators were arrested for throwing beer in the faces of the Australian batsmen as they were going up to the dressing room.

"They will also face charges of crimen injuria."

She added: "Gerald Majola spoke to the Australian team manager Steve Bernard.

"He has apologised for both incidents. But obviously the UCB makes a very strong appeal to South African spectators to respect the opposition - and especially in the run-up to the World Cupt."