South Africa edged the West Indies by three wickets in a rain-affected Super Eights match on Sunday to reach the T20 World Cup semi-finals and eliminate the hosts.

Chasing a revised 123 off 17 overs, South Africa stuttered to 110-7 as Roston Chase took three wickets, but they reached their target when Marco Jansen hit the first ball of the final over for six.

Man of the match Tabraiz Shamsi took 3-27 after South Africa won the toss and restricted the West Indies to 135-8 at the Sir Vivian Richards Stadium in Antigua.

All-rounder Chase top scored with 52, featuring in an 81-run third-wicket partnership with Kyle Mayers (35 off 34 balls) before giving the West Indies hope by taking 3-12 with his off-spin.

Jansen's unbeaten 21 saw the Proteas to victory at 124-7 when he smashed the final six off Obed McCoy.

"The last time I played here I went for 50 runs and there was a lot of chatter going around," said Shamsi.

"I was happy to come back and perform my role, but credit as well to the guys who bowled before me because they set it up beautifully."

Brought in for seamer Ottneil Baartman, the left-arm wrist-spinner got excellent support from fellow slow bowlers Keshav Maharaj (1-24) and captain Aiden Markram (1-28).

Chase was dropped on 11 by Anrich Nortje and made the most of his luck, clearing the ropes twice and hitting three fours.

His partnership with Mayers helped rescue the hosts after they fell to 5-2 in the second over.

Once Shamsi removed Mayers to a sliced catch at deep cover, a steady stream of wickets enabled South Africa to restrict the West Indies.

With the score on 117-6, Nortje made amends for his earlier error with a direct hit to run out the dangerous Andre Russell who had hit two sixes in his 15 off nine balls.

"This is one batting performance we will try our best to forget," said West Indies captain Rovman Powell.

"It was a commendable bowling effort by us. We said at the halfway mark that we were going to give it our all and the guys really gave everything to defend that total."

Winning captain Markram admitted to nerves during the tense chase.

"There's a lot of relief at making the semi-finals but we're not going to be brainwashed by that because we would have liked to be a lot more convincing,"  he said.

"Maybe we tried to kill off the game too early, but that's been the story of the competition so far.

"We get ourselves into tricky positions and then have to battle to get over the line."

South Africa join England as the semi-final qualifiers from Super Eight Group 2.