Danny Ings and Henrikh Mkhitaryan both hit braces before Bernd Leno came and missed Shane Long's cross to allow substitute Austin to head the host to its first victory in 15 outings.

Much of the build-up centred on the role Laurent Koscielny, starting his first top-flight match since April, would play in stabilising a makeshift three-man defence, yet it was he who twice lost Ings for a pair of first-half headers.

Mkhitarayan replied with one of his own before the break and levelled for the second time with a deflected 53rd-minute shot, but the Gunners' second-half fightback stopped short on this occasion as they were left three points adrift of the top four.