Barnsley boss David Flitcroft was ecstatic after his team beat promotion hopefuls Hull with a shock 2-0 win.
Victory for the visitors would have ensured Premier League football for next season, while the Tykes began the day in the relegation zone.
It was a nervy display by Steve Bruce's men, while it was a huge boost for Barnsley and Flitcroft said: "It's massive, isn't it?
"I think the occasion - the last home game - again we're only two weeks away from getting crushed and in a lot of people's minds the season was over against Charlton.
"The courage, the bravery they've displayed; but also the quality was on show. That was evident today."
With one game remaining, it may work out that Barnsley do not need all the spoils at Huddersfield to survive.
But a reinvigorated Flitcroft said his team now had "ridiculous momentum".
"If we turn up with that energy we're going to be a match for anyone in this division and that's what we've certainly showed since I took the job."
The winning goal came courtesy of debutant Joe Bunney's first touch in professional football, the young striker heading home in the 78th minute shortly after coming on from the bench.
The Pilgrims' quest suffered a serious setback 14 minutes in when Maxime Blanchard was dismissed for a foul on George Donnelly.
The Rochdale striker had lifted the ball over Blanchard's head and was advancing towards goal when the defender hauled him down, referee Geoff Eltrincham deeming it a red-card offence.
Rochdale took control after that and Jake Cole pulled off good saves to deny Donnelly and Reece Gray, while Michael Rose's 35-yard drive smashed against the underside of the crossbar.
The visitors saw their appeals for a penalty waved away when Wayne Thomas appeared to foul Joe Bryan, but the home side continued to ask most of the questions.
And they clinched the win when, minutes into his debut, Bunney headed home fellow substitute Scott Tansey's cross from six yards.