Toulouse claimed the European Champions Cup for a record fifth time with a narrow win against 14-man La Rochelle in front of 10,000 fans at Twickenham.
La Rochelle centre Levani Botia was sent off for a dangerous tackle after 30 minutes but his side led 12-9 after a physical first half.
Juan Cruz Mallia scored the first try after an hour to put Toulouse ahead.
Tawera Kerr-Barlow dived over for La Rochelle late on to ensure a gripping finish but Toulouse held on.
The win gave Toulouse their first victory in the competition since 2010, making them the first French side to win the title since Toulon six years ago.
Mallia's try and a fifth penalty from the boot of Romain Ntamack shortly after looked to have given Toulouse enough distance from their tiring opponents, but first-time finalists La Rochelle fought back bravely.
Had Ihaia West not hit the post with two of his kicks at goal - firstly with a penalty and later when trying to convert Kerr-Barlow's try - La Rochelle might have claimed a memorable victory.
The win saw fly-half Ntamack match his father Emile, who was part of the Toulouse side that won the first Champions Cup in 1996.
Toulouse take their time
Toulouse eventually made their numerical advantage count in the second half after going into the break 12-9 down.
Referee Luke Pearce could not award a try when Richie Arnold burrowed over the line at 12-12 due to lack of "compelling evidence" that the lock had touched down.
But Ntamack sparked his side into life when his long pass missed out two to find Thomas Ramos, who fed the ball back inside him to allow Mallia to race over.
And with seconds remaining as La Rochelle tried to reclaim the ball, Ntamack gave his side a fright as he was caught in possession as 80 minutes loomed on the clock before Antoine Dupont hacked the ball off the field.
Ill discipline costs La Rochelle
There was little to choose between the two sides as Ntamack and West exchanged penalties until the turning point came with the score at 6-6.
Botia charged in on Maxime Medard with his shoulder, catching the Toulouse full-back flush on the neck, and was initially shown the yellow card having encroached within 10 metres at a penalty.
But referee Pearce reviewed it and then flashed the red card at the Fiji centre while the 32-year-old sat in the sin bin.
However, the side coached by former Ireland fly-half Ronan O'Gara shook off the loss of Botia to keep pressurising Toulouse, and thanks to West's boot they led 12-9 at the break.
Despite going more than a converted try behind with time running out, La Rochelle showed huge determination and scrum-half Kerr-Barlow pounced from close range to set up an enthralling climax.
As well as Botia's lack of discipline and West's missed kicks, O'Gara's side will also rue the moment when hooker Pierre Bourgarit spilled the ball over the tryline at 12-12 but they emerged from their first Champions Cup final with great credit.
Analysis
Harlequins and England scrum-half Danny Care on BBC Radio 5 Live:
You have to feel sorry for La Rochelle after the effort they put in when down to 14 men but it's euphoria for Toulouse to win their fifth title.
They have world-class stars but Antoine Dupont is the heart of the Toulouse team. He makes big tackles and he's the guy that sparks the attack when they get a chance to score. He's the deserved European player of the year.
Line-ups
La Rochelle: Dulin; Leyds, Doumayrou, Botia, Rhule; West, Kerr-Barlow; Priso, Bourgarit, Antonio, Sazy, Skelton, Alldritt, Gourdon, Vito
Replacements: Bosch, Wardi, Joly, Lavault, Liebenberg, Boudehent, Retiere, Plisson
Toulouse: Medard; Kolbe, Mallia, Ahki, Lebel; Ntamack, Dupont; Baille, Mauvaka, Faumuina, Rory Arnold, Ritchie Arnold, Elstadt, Cros, Kaino
Replacements: G Marchand, Castets, Ainu'u, Tekori, Flament, Tolofua, Germain, Ramos.
Referee: Luke Pearce (England)