Quade Cooper was a last-minute withdrawal after straining his left calf in the warm-up on Saturday night, but it was the injury to Banks that left viewers squeamish.
After leaping high into the air in a bid to catch Nic White's 22nd-minute restart, Banks' left arm bent the wrong way as he crashed to the ground.
The 28-year-old immediately realised the extent of the damage, and he was in clear pain as he was taken off the field on a medicab.
Adding to the Wallabies' woes, prop Allan Ala'alatoa went off in the 26th minute after copping a knock to the head and he was unable to return.
The night of injury carnage for the hosts started even before kick-off.Â
The Wallabies were completing their warm-up at Optus Stadium when Cooper injured his left calf.
The 34-year-old was consoled by teammates as he slowly trudged off the field.
Noah Lolesio was thrust into the starting line-up in place of Cooper at No.10 while James O'Connor was brought onto the bench.
Cooper led the Wallabies to five straight wins last year after his four-year exile from the national side came to an end, and his absence leaves a massive void.
O'Connor was part of a corporate function before the match but he was rushed to the rooms to get changed once Cooper's injury was confirmed.
Lolesio played a key role in the win, nailing all three conversions to go with three-of-three penalties to keep England at bay.
His last two conversions - from near the sideline - were particularly crucial, given the Wallabies were down to 14 men following the 34th-minute red card to lock Darcy Swain.
O'Connor entered the field late in the match, but by then the contest was already won, with two late tries to England - including one after the final siren - only adding respectability to the scoreline.