At 162 for seven, all the principal batsmen gone and needing another 82 runs in 15 overs there seemed no way back for the tourists. Yet when Ashley Giles struck the winning boundary with three balls to spare home supporters and a small gathering of the Barmy Army rose in unison to record their appreciation of an unlikely victory.
This was England's sixth success in eight games and avenges their one defeat, in the opening match, by New South Wales. Who is to say that with the spirit and energy this side have shown they cannot maintain their winning ways in the crucial last week of the trip?
England A go to Woollongong to meet NSW in another limited-overs affair tomorrow and then take on the unbeaten Sheffield Shield leaders Queensland in Brisbane in a first-class contest.
What made England's win even more eye-catching is that they were effectively
a batsman short: Mark Butcher had a migraine and was absent for the first time while Jason Gallian's damaged finger again kept him out.
If Butcher had been fit Dean Headley would not have played. As it was, the Kent fast bowler - himself not 100 per cent fit was a central figure in the result.
After NSW had been put in, he bowled out his 10 overs conceding a mere 26 runs, then came in to hit an unbeaten 20 off 22 balls and share with Giles in the dramatic ninth-wicket partnership of 42 in eight overs.
Michael Slater, Australia's deposed Test opener, showed why he is presently out of favour by slashing at Glen Chapple's swinging wide delivery in the second over and edging to Warren Hegg.
The home side were only 99 for three after 30 overs before England came under the hammer from Somerset's Shane Lee who hit a magnificent 113 off 103 balls, including eight fours and a huge six off Giles.
Kevin Roberts gave one hard chance off Mark Ealham but went on with Lee to add 117 in 105 deliveries. Lee eventually skied Adam Hollioake to mid on but that was in the final over by which time he had run England ragged. On the same pitch where Australia had beaten West Indies 48 hours earlier, with the ball coming on so slowly, NSW's 243 for six looked to be out of reach.
Greg Matthews, the home captain, neither bowled nor batted and it was off-spinner Gavin Robertson who carried NSW's hopes. He finished with four for 46 but England helped to make a rod for their own backs with three run-outs.
With a middle order collapse, three wickets going down for 19 runs in six overs, there seemed little hope for the tail - even if NSW were without their five Test players.
Ealham was first to be run out and gave his captain an old-fashioned look when Hollioake refused to come back for a second. Then Hollioake himself suffered a similar fate as soon as he had passed his half-century, Giles sending him back. Chapple was the third victim, ending sprawled in the dust, but he played a heroic part in an eighth-wicket stand of 47 in nine overs.
When Headley arrived the asking rate was hovering at six. By the start of the 49th 12 were still needed before Headley played an instinctive shot, dabbing down on a yorker and sending it screaming to the midwicket boundary.
So when Giles cover drove Brad McNamara for the winning four, he was fully entitled to charge about waving his bat like a sabre, having hit 39 at a run a ball.