Subrayen was drafted into the Super Kings' line-up after missing the first game and immediately made an impact on a slow surface.
The Proteas off-spinner took the wickets of overseas trio Devon Conway, Kane Williamson and Jos Buttler as the Super Giants were bowled out for just 86 in 17.1 overs.
Subrayen finished with figures of 3-16 in his four overs while English fast bowler Richard Gleeson took three lower-order scalps.
Home captain Aiden Markram tried his best to get his team to a competitive total but perished for 22.
The Super Kings were in early trouble in the run-chase as skipper Faf du Plessis, Matthew De Villiers and Wiaan Mulder all fell cheaply with only 24 runs on the board.
Rilee Rossouw made sure the visitors would have no further hiccups with 43 off 32 deliveries only to lose his wicket near the end.
USA international Shubham Ranjane (15 not out) and Donovan Ferreira (12 not out) made sure the Super Kings reached the target in the 13th over which also ensured they took a bonus-point from the contest.
Sunrisers Eastern Cape secured their second consecutive bonus-point victory in this season's SA20 after beating the Pretoria Capitals by 48 runs at St George's Park in Gqeberha on Monday.
Anrich Nortje will put in the hard work with the Sunrisers Eastern Cape in the SA20 as he aims to be selected in the Proteas squad for the T20 World Cup.
Persistent rain ensured there was little cricket on offer as the SA20 clash between Durban’s Super Giants and MI Cape Town at Kingsmead on Sunday was abandoned after just four overs.
Joburg Super Kings claimed their first win at Centurion in four seasons by beating Pretoria Capitals, while Paarl Royals were demolished by Sunrisers Eastern Cape.
