Simon Harmer and Kagiso Rabada bowled South Africa to a series-clinching 176-run win on Saturday after Australia collapsed to 111 all out at Newlands in the third and final Test.

Rabada took two wickets in the first over and followed up with a third in a devastating opening spell which ripped out Australia’s top three batsmen after they had started the day needing 288 to win.

Off-spinner Harmer took a career-best six for 16 in 21.1 overs as South Africa completed their win shortly before tea.

“It was about getting the win today, worked out nicely. The way KG (Rabada) took three wickets, after that it was about playing for a draw for them,” said Harmer, who had match figures of 10 for 120.

“To be able to bowl in that situation, guys around the bat, the theatre, creating pressure, goes a long way and makes my job easier.”

Josh Inglis was run out to add to Australia’s woes after Rabada’s initial burst before Harmer took two wickets in three balls to plunge the tourists to 42 for six.

Australia were 60 for seven at lunch when Mitchell Starc was caught at short leg but in keeping with a series of multiple changes of fortune, South Africa were kept in the field for another two hours before completing their win.

Nathan Lyon finished as Australia’s top scorer with an unbeaten 33 after Harmer removed Cameron Green for 27. Harmer pinned Pat Cummins in front and then bowled Josh Hazlewood to seal victory.

South Africa, the defending World Test champions, went past Australia to the top of the International Cricket Council’s Test rankings at the end of a series in which all three matches produced a result on the fifth day.

Travis Head scored a single off Rabada’s second delivery but Matt Renshaw, Australia’s most successful batsman in the series, was out first ball, glancing Rabada down the leg side to a diving wicketkeeper Ryan Rickelton.

Three balls later the out-of-form Marnus Labuschagne padded up to a ball which swung in sharply and was given out leg before wicket, with a review showing umpire’s call on off stump.

Head fell to a reflex catch by Marco Jansen at gully as the left-hander flashed at Rabada and the South African players celebrated the demise of a batsman capable of playing a match-changing innings.

“We didn’t give ourselves a chance today,” said Cummins.

“We’re a really good side. Tough opponents away from home, that’s difficult. We came here thinking we are good enough to win, but we weren’t.”