Career-best performances from Marco Jansen and Keshav Maharaj have propelled South Africa to a 122-run thrashing of inept Australia at a raucous, sold-out Wanderers Stadium in Johannesburg, as the Proteas eased to a 3-2 ODI series triumph.

Jansen’s thrilling 47 off 29 balls helped the home side amass 9-315, before his 5-39 and Maharaj’s 4-33 with the ball helped skittle Australia for 193 in reply at the Bullring on Sunday (Monday morning AEST).

After sweeping the Proteas 3-0 in the Twenty20s, Australia had marched to a 2-0 ODI series lead but their tour has ended disastrously, crushed by 111, 164 and 122 runs in the last three fixtures while also losing gun opener Travis Head to a fractured hand at Centurion.

Australia’s bowlers were treated with disdain in the back half of the tour, while the tourists’ brisk starts with the bat were repeatedly undermined by huge collapses, all worrying signs leading into the World Cup.

Captain Mitchell Marsh (71) and Marnus Labuschagne (44) added 90 for the third wicket before their back-to-back dismissals sparked a horror 8-69 collapse.

Jansen started with a double-wicket maiden in his first over, sending danger man David Warner (11) and Josh Inglis (0) packing.

Jansen gave World Cup hopeful Labuschagne – the series leading runscorer with 283 at 70.75 – a real working over early and he should have had Marsh for 35 but for a moment of confusion in the field.

Marsh’s miscued shot sailed high in the air before the ball plopped between Gerald Coetzee in the outfield and Aiden Markram at midwicket, Coetzee the guilty party.

After crunching Jansen for successive sixes, Marsh’s attempted third maximum in the over proved his downfall, uppercutting to Lungi Ngidi on the third man boundary.