Australia crushed Russia 68-22 to secure their place in the Rugby World Cup quarter-finals on Saturday in Nelson but suffered another injury blow when winger Drew Mitchell, who scored two of their 10 tries, pulled a hamstring as they lost their way in the second half.
The Wallabies scored the bonus point fourth try in the first 15 minutes and eight before half-time, when they led 47-5.
Berrick Barnes, David Pocock and Mitchell scored two tries each.
But Russia equalled the second-half try tally with both sides scoring a pair after the break, and the utility Mitchell suffered what looks like a tournament-ending hamstring injury on the way to what would have been his hat-trick - adding to coach Robbie Deans' problems.
Deans was forced to field No.8 Radike Samo on the right wing due to the number of injuries plaguing his side.
Australia join New Zealand and South Africa in the last eight and they might have to beat both their Tri-Nations rivals to reach the final if Ireland beat Italy on Sunday to finish top of Pool C.
Russia exit the Cup without a win in their first-ever tournament.