Steyn (right) dismissed Morton despite bowling with a hamstring injury

South Africa reduced West Indies to a second-innings score of 96-4 at stumps on day three of the second Test to close in on a series-levelling win.

Earlier, South Africa reached 321 for a first-innings lead of 78, with Ashwell Prince making 98 before being run out.

West Indies batted doggedly in response and put on 59 for the first wicket as they scored at less than two an over.

But by the close in Cape Town they were just 18 runs ahead, and captain Chris Gayle was batting with a runner.

Gayle, suffering from a hamstring problem, came to the wicket at the fall of the fourth wicket with 15 minutes of play left.

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Gayle and Shivnarine Chanderpaul saw the day through to the close but they will need to produce a superb partnership on day four if they are to dent South Africa's hopes of winning the second Test.

The home team had resumed in the morning on 218-5 and added a further 103 runs, thanks largely to the superb sixth-wicket partnership between Prince and Mark Boucher.

The two batsman had already put on 87 coming into the third day and added a further 42 before Boucher played on, bottom-edging an attempted pull off Dwayne Bravo.

Prince played a watchful and patient innings that probably deserved to reach three figures but he tried to take a second run to the arm of Jerome Taylor at third man and was comfortably run out.

By that stage the Proteas had 301 on the board and the makings of a comfortable first-innings lead given the attritional nature of the match.

A late flourish from Dale Steyn (21) took them further ahead before Graeme Smith's bowlers set about the West Indian opening pair.

Gayle was unable to open after missing a large period of time in the field with a hamstring injury so wicket-keeper Denesh Ramdin deputised alongside Daren Ganga.

The two made painfully slow progress as they chipped away at the South African lead but had reduced the arrears to 19 when Ramdin edged a superb ball from Jacques Kallis.

Makhaya Ntini, Andre Nel and Steyn, bowling despite a hamstring injury, all struck as the visiting team lost wickets at steady intervals.

By the close the West Indies had mustered a meagre 96 runs in 50 overs, while Nel had bowled 15 overs for 14 runs.

The close of play also coincided with the news that Fidel Edwards will not be able to bowl in the remainder of the Test because of a hamstring injury that restricted him to 4.5 overs in the South African innings.