South Africa gave themselves a chance of victory in the second Test after the West Indies collapsed late on day four.
The match in Port Elizabeth has been disrupted by bad light and rain, and Monday's play was no different as only 35 overs were possible at St George's Park.
In reply to South Africa's first-innings 417-8 declared, the tourists resumed on 147-2 with Kraigg Brathwaite and Marlon Samuels both in the 60s.
The pair progressed well at first, both reaching their centuries in a partnership worth 176, the highest for the third wicket for West Indies against South Africa.
But when both men fell in consecutive overs, that double blow sparked a collapse as Imran Tahir (3-108) found some form with the ball.
Windies lost seven wickets for 44 runs and were still 142 behind on 275-9 when the conditions brought a premature end to the day's play.
Both Brathwaite (106) and Samuels (101) had to survive a barrage of short-pitched deliveries from Morkel (4-69) and Dale Steyn (0-48) in the early exchanges.
Brathwaite was given a reprieve on 90 when Faf du Plessis shelled a chance back-pedalling from slip after the opener had fended off a short ball from Steyn.
He went on to reach three figures soon afterwards with a cut to backward point for two.
His partner reached the landmark in style, swatting a full toss from Tahir to the midwicket fence.
Samuels fell in the next over, however, pinned lbw my Vernon Philander (1-41), and South Africa claimed a second scalp in as many overs as Brathwaite edged Morkel to Alviro Peterson at slip.
Skipper Denesh Ramdin was next to go, trapped in front by Tahir for 20, and the legspinner then took the crucial wicket of Shivnarine Chanderpaul for just seven.
So often a stubborn customer in the Windies order, Chanderpaul was a little unfortunate to defend a ball from Tahir which bounced down onto the ground, through his legs and dropped onto the top of leg stump.
Morkel had Jason Holder caught behind for one, before Tahir accounted for Sulieman Benn (four), and Steyn ran out Kenroy Peters (duck) with the final ball before the weather closed in.
South Africa will now hope for a full day's play on Tuesday, as they look to clinch the final wicket and then mount a push for victory and what would be an unassailable 2-0 lead in the three-match series.