Brazilian Lucas Ribeiro scored twice as Mamelodi Sundowns stretched an unbeaten South African Premiership run to 30 matches by winning 2-0 at Polokwane City on Wednesday.

The record 13-time champions have not lost since September 2 last season when going down 2-1 to SuperSport United in a Pretoria derby.

Victory over Polokwane was the sixth in a row since this season kicked off and took Sundowns eight points clear of second-placed Golden Arrows and SuperSport.

Ribeiro joined Sundowns in mid-year from Belgian club SK Beveren and his four goals make him the early frontrunner for the Premiership Golden Boot award.

He converted a 12th-minute penalty and struck again five minutes into the second half with a tap into the net after goalkeeper Lindokuhle Mathebula could only parry a Themba Zwane shot.

Despite seven victories since the season kicked off -- they also won a cup tie -- Sundowns coach Rulani Mokwena was not satisfied with the performance in Polokwane.

"We should have scored more goals. Finishing is an area requiring improvement. What did please me was the way we contained Polokwane. They had zero scoring chances," said Mokwena.

A Kaizer Chiefs revival continued with a 2-0 win over Stellenbosch in Cape Town through second-half goals from Pule Mmodi and Congolese Christian Saile.

After taking only one point from three league matches, this was the second straight win for the most popular club in South Africa, and lifted them to fifth.

They are one place behind arch rivals Orlando Pirates, whose 2-0 win over Cape Town City in Soweto on Tuesday was marred by a controversial second goal, which Patrick Maswanganyi scored.

"It was not a goal -- the ball did not cross the line. We need VAR in South Africa," said City coach Eric Tinkler.