Fourth-placed Victoria gave their Sheffield Shield finals hopes a boost by grabbing first-innings points against South Australia on Tuesday.

Medium-pacer Andrew McDonald took advantage of a lively MCG pitch to claim 5-21 as South Australia collapsed for 100 on Tuesday’s second day’s play.

The Redbacks had resumed on 4-81 in reply to Victoria’s 220 and Michael Klinger’s men folded in spectacular style, losing 6-19 in 15 overs.

Victoria reached 0-47 in their second innings at lunch, an overall lead of 167, with Chris Rogers on 34 including six boundaries and Rob Quiney on 12.

Victoria’s Test quick Peter Siddle (3-34) removed Travis Head lbw for two in the second over of the day on Tuesday and Adam Crosthwaite was caught behind for a duck off McDonald.

McDonald claimed the key wicket of South Australia’s leading scorer this season Tom Cooper who was bowled for 15 and Siddle broke through Joe Mennie’s defences for three at 8-99.

McDonald picked up his fourth wicket when Carl Tietjens was caught at third slip.

Peter George also fell to the former Test allrounder McDonald, whose 5-21 came off 16 overs in a stunning effort.

Young seamer Mennie took 5-43 on Monday to continue his fine debut season for South Australia after McDonald (72) and Siddle (41) added 95 for Victoria’s eighth wicket to rescue the innings from a precarious position at 7-118.