Ndabayithethwa Ndlondlo netted a brace, while Monde Mpambaniso and Edgar Manaka weighed in with a goal apiece for a one-sided victory at the Dr Petrus Molemela Stadium.
Gallant's were subsequently paired with Golden Arrows in their semis as Richards Bay were drawn to face Orlando Pirates.
Arrows overcame TS Galaxy 2-1 in their quarter-final clash, while Pirates beat Magesi 2-1, as Richards Bay saw off Durban City 3-1.
All the dates, venues and kick-off times will be announced by the Premier League.
The full semi-final draw:
Golden Arrows vs Marumo Gallants
Richards Bay vs Orlando Pirates
Marumo Gallants coach Alexandre Lafitte says the 4-0 defeat to Golden Arrows in the Betway Premiership last weekend is motivation to reach the Carling Knockout final.
Golden Arrows coach Manqoba Mngqithi says he is expecting a 'different' Carling Knockout Cup semi-final match against Marumo Gallants at King Zwelithini Stadium on Sunday.
TS Galaxy returned to winning ways with a 2-0 victory in the Betway Premiership over Stellenbosch at the Mbombela Stadium on Sunday.
Golden Arrows head coach Manqoba Mngqithi has showered praise on winger Siyanda Ndlovu, describing him as one of the most exciting football talents in South Africa today.
