Sundowns defeated MC Alger 2-0 in Pretoria on Saturday to finish second in Group C behind Al Hilal, who recorded a 1-0 win over St Eloi Lupopo at the same time.
Al Hilal top the pool with 11 points, with Sundowns (9 points) in second, followed by MC Alger (7) and St Eloi Lupopo (5).
Both goals were scored by Colombian forward Brayan Leon as he continued his fine start to life in South Africa following a January move.
Leon opened the scoring inside six minutes to settle the nerves at Loftus Stadium in a game Sundowns had to win to advance.
He showed great technique to fire in a rebound after a shot was initially saved, keeping his effort low and on target.
His second came just past the hour-mark as Aubrey Modiba’s low cross from the left was turned in at the near post by Leon.
Sundowns dominated possession and chances, with the Algerians battling to make an impact in the final third.
It will be sweet relief for Sundowns coach Miguel Cardoso, who would have been under extreme pressure had his side failed to make the knockout rounds. He led them to the final of the competition last season, where they lost to Egyptian side Pyramids.
The match was also marred in the build-up by accusations that Sundowns analyst Mario Masha had shared team tactics with MC Alger coach Mokwena, something both parties stringently deny.
The draw for the CAF Champions League quarter-finals is scheduled for this coming week, with CAF yet to confirm the specific date.