Northampton fought back from being 22-6 down and having Tom Wood sent off to secure a thrilling 23-22 win over Stade Francais and secure European Champions Cup rugby next season.
In a barnstorming play-off at Franklin's Gardens all looked lost for the home side when Wood was red-carded deep in the second half.
With Rory Hutchinson already in the sin-bin Saints were two men down and 22-16 behind with seven minutes left.
But a superb finish from Ahsee Tualau saw him shake off three men to score and then Harry Mallinder landed the touchline conversion to seal a fantastic comeback after conceding three tries in the first half.
Northampton had the worst possible start with Waisea Nayacalevu scoring a try in the third minute. Jules Plisson converted and added a penalty to leave Saints 10-0 behind after seven minutes.
In a frantic opening 20 minutes Mallinder finally got the home side on the board with a penalty, but when Stade were awarded a penalty Australian international Will Genia caught Saints napping.
He tapped it and then passed to substitute Meyer Bosman, fresh on the field, who burst into the 22 and flung a superb pass to Jeremy Sinzelle to score in the corner. Plisson missed the conversion but the home side were now 15-3 down.
On 30 minutes Mallinder clipped over his second penalty, but Stade scored their third try thanks to an uncharacteristic mistake from Saints' player of the year Louis Picamoles.
The France international dropped a pass five metres from his own tryline and from the scrum Genia darted towards the line before passing to Djibril Camara who skated round under the posts. The crowd were screaming for a forward pass, but referee John Lacey refused to go upstairs and Plisson converted to make it 22-6.
Mallinder added a third penalty on half-time, and it was the fly-half who broke clear to start the stunning comeback straight after. A searing run saw hooker Remi Bonfis try to trip Mallinder up. It earned the Frenchman 10 minutes in the sin-bin.
Saints took advantage, setting up camp in the Stade 22 and Ben Foden timed his run perfectly to sear through the French side's determined defence from seven metres. Mallinder converted and suddenly there was hope at 22-16.
Despite being a man down the blistering pace of full-back Camara twice nearly brought a try and Northampton were dealt a blow when replacement centre Hutchinson was sin-binned on 62 minutes for taking Genia out in the air.
And it got even worse a minute later when captain Wood was sent off for a stamp on Camara's head in a ruck, even though the TV pictures looked inconclusive.
But with 13 men Saints still piled forward and a wonderful 20-metre pass from Mallinder saw Tuala twist and twirl through three men to touch down. And Mallinder then calmed himself down to land the touchline conversion and put the home side one point ahead. The Saints held out for the final minutes to seal a hugely important victory.