Rayners, who scored all five goals in a rout of Polokwane City last Saturday, has netted 14 times in the league, once more than Tshegofatso Mabasa of Orlando Pirates.
Victory at home stretched the unbeaten run of Stellenbosch in all competitions to 25 matches, and 10 points from their remaining four league matches will guarantee a Champions League place.
South Africa are allocated two places in the premier African club competition and one slot has already been filled by runaway leaders Mamelodi Sundowns.
If Sundowns win away to Kaizer Chiefs in Johannesburg on Thursday, they will clinch a seventh straight league title with six matches to spare.
Orlando Pirates stayed third, three points behind Stellenbosch, with two second-half goals from Mabasa delivering a 2-0 victory at Cape Town City.
Rising star Relebohile Mofokeng created both goals, which Mabasa scored after 59 and 73 minutes against opponents who faded after holding their own in the opening half.
“Finally, a win,” said Spanish coach Jose Riveiro, referring to Pirates losing to Cape Town Spurs and Stellenbosch this season on previous visits to the western Cape.
“I am a very lucky coach, having so many quality players to choose from. We gave an outstanding performance on a pitch that was not ideal.”
Coached by South African Steve Barker, Stellenbosch face AmaZulu and Sundowns at home and Moroka Swallows and Richards Bay away in their Premiership run-in.
The club based in the Cape winelands, 53 kilometres (33 miles) east of regional capital Cape Town, came fourth two seasons ago in their best Premiership finish.
Pirates were runners-up last season, four places above Stellenbosch, and are seeking a 13th Champions League appearance.
The club finishing third qualifies for the CAF Confederation Cup, the African equivalent of the UEFA Europa League.
© Agence France-Presse
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