Dogged van der Dussen digs Proteas out of trouble

The West Indies' hopes of saving their two-match series against South Africa have risen and fallen on the third day of the second Test, subsiding in the face of a dogged half century from Rassie van der Dussen.

Leading by 149 after the first innings, South Africa slumped to 7-73 in the second as they struggled against quality fast bowling from Kemar Roach and Kyle Mayers.

But van der Dussen made an unbeaten 75 and shared a vital 70-run partnership for the eighth wicket with Kagiso Rabada, who made 40 from 48 balls, to diminish the hosts' chances.

South Africa were finally out for 174, building a lead to 323 which may be beyond the reach of the West Indies whose best total of the series so far is 162.

Openers Kraigg Brathwaite (5 not out) and Kieran Powell (9 not out) batted out the last six overs of the day in fading light to guide the West Indies to 0-15 at stumps - needing another 309 runs to win.

The task of chasing that total in the fourth innings is difficult on a wearing pitch, especially for a West Indies team whose batsmen have struggled throughout the series.

The hosts might also be without Roston Chase who has a leg injury.

But Brathwaite will take heart from the memory of the West Indies' successful chase for a similar total against England at Headingley in 2017, when he scored 134 in the fourth innings.

Van der Dussen showed Sunday that runs can be scored with application.

He batted through more than 40 overs to steady the Proteas' innings.

"I was a bit of a hiccup at the start of our innings... ," van der Dussen said.

"We're happy with the position we're in now. It would have been nice to have a wicket tonight but we'll be backing ourselves to get the job done tomorrow."

South Africa won the first Test, also in St. Lucia, by an innings and 63 runs.