In an instant, Australia lost 3-3 late on day four, putting their first Test hopes on life support.
Australia's frustration over Stuart Broad's not out nick on day three was compounded by further heartbreak at the hands of DRS.
At stumps, the tourists were 6-174, requiring another 137 runs to win with four wickets in hand.
The good news is there's still hope.
A frantic incident in the 59th over gave the extraordinary Ashes opener in Nottingham another twist.
Again Broad, Australia captain Michael Clarke and umpire Aleem Dar were at the centre of the controversy.
Broad (2-34) and England went up for a caught behind appeal off Clarke, with Dar originally not raising his finger but going to DRS to check whether wicketkeeper Matt Prior had taken the catch cleanly.
When replays showed Prior had, Dar raised his finger.
However, Clarke immediately signalled for a review as tensions grew out in the middle and the partisan crowd jeered their disapproval.
HotSpot showed a faint mark on the side of Clarke's bat and he was given his marching orders.
With that, Australia's hopes of victory took a major dip.
The very next ball, Steve Smith was out lbw to Graeme Swann (2-64) at the other end.
Because Clarke had wasted Australia's final challenge, Smith couldn't go upstairs, but it wouldn't have mattered anyway - he was plumb.
Then two overs later, Phil Hughes was given out lbw in an agonisingly unlucky DRS overrule.
Hughes had been given not out on the field and replays seemed to suggest Swann had hit him outside the line.
But hawk eye showed enough of the ball had pitched.
That made it four umpire's calls that have gone against Australia this Test match.
Clarke's decision to review his dismissal was another moment of controversy and will yet again ignite the debate about whether players should walk or exercise their right to let the officials make the call.
Batsmen usually know when they've nicked the ball and Clarke's call for a lifeline appeared to be a desperate measure to try to get some luck out of the DRS.
Back in the 2010 Ashes Test at Adelaide, Clarke stood his ground on a similar incident, but was given out when an England review showed he was clearly caught.
Later, Clarke tweeted an apology.
Cowan's Test career is now in significant doubt.
Earlier, Ian Bell (109) and Broad (65) put on 138 to power England to 375 in their second innings and set Australia 311 for victory.
If Australia can chase down the target, it will be the highest successful run chase at Trent Bridge and one of the biggest in the history of the baggy green.