West Indies 149 (Blackwood 49, Mulder 3-1) and 15 for 0 (Powell 9*, Brathwaite 5*) need another 309 to beat South Africa 298 (de Kock 96, Mayers 3-28, Roach 3-45) and 174 (van der Dussen 75*, Roach 4-52)
St. Lucia: West Indies were 15-0 in their second innings at the close of play on a rain-interrupted third day of the second test in Saint Lucia on Sunday after being set an imposing 324 to beat South Africa and share the series.
Kieran Powell and captain Kraigg Brathwaite will return on Monday to the Daren Sammy Cricket Ground to resume a difficult chase but with two days remaining.
It might have been a less onerous task had the Windies finished off the South African tail after having the tourists reeling at 73-7 in their second innings but allowed them to recover and reach 174 before being dismissed.
Rassie van der Dussen hit an unbeaten 75 and featured in a 70-run partnership for the eighth wicket with Kagiso Rabada to significantly build on the 149-run lead South Africa enjoyed after the first innings.
Rabada scored a test-high 40 as he and Van der Dussen frustrated the home attack, for whom Kemar Roach took four wickets for 52 and Kyle Mayers 3-24.
Rain meant play only started after lunch and South Africa were in immediate trouble at the start of their second innings, losing Aiden Markram in the first over and seeing a steady procession of batsmen heading back to the pavilion.
Captain Dean Elgar made just 10, after a gritty half century in the first innings, while Quinton de Kock, after scoring 96 on Saturday, lasted just two balls as he edged Jason Holder behind.
But the West Indies attack looked to run out of steam just when they were in a position to dismiss the touring side cheaply.
Facing a target over 300 will be daunting for the home side who managed only 97 and 162 in their two innings in the first test, which they lost by an in innings and 63 runs.