Maxime Machenaud's late penalty ensured that Racing 92 will face Leicester in the Champions Cup semi-finals after beating Toulon 19-16.
Juan Imhoff scored the opener two minutes in but was matched by Charles Ollivon in a closely fought first half.
The sides were level for most of the second half until Maxime Machenaud stepped up with two minutes to go and kicked through the winning points.
With Leicester Tigers qualifying, victory for either side meant they will face Richard Cockerill’'s side in the final four.
The hosts had a three-point lead within the first minute of the tie, Dan Carter slotting a penalty through almost straight from the restart.
Racing burst out of the blocks superbly and they had a 10-point lead after just four minutes. Imhoff nipped in after Maxime Mermoz’'s weak pass was intercepted and there was no stopping the Argentina star as he stormed towards the line. Carter converted and Toulon had been blown away just four minutes into the tie, down 10-0.
But despite the dreadful start, the holders levelled the try scoring from their next attack. Still inside the first 10 minutes, Charles Ollivon went over after a fine break forward from Josua Tuisova. Jonathan Pélissié converted and Toulon dragged themselves back into contention.
After that breathtaking first 10 minutes, the half calmed down as both sides reverted to a more defensive nature.
Pélissié had two opportunities within three minutes to put his side at the very least level, but the first hit the upright whilst the second was off target.
Maxime Machenaud missed a kick for the hosts in the absence of the temporarily injured Carter, and by half-time Toulon were level. Pélissié kicking over seconds before the break and the sides went in 10-10.
The Toulon kicker put the visitors ahead for the first time three minutes into the second half with another penalty.
Machenaud responded to make it 13-all and keep the game finely poised. The scrum-half again kicked another three through to restore the lead they built up early on, with Pélissié missing his third kick of the afternoon a minute later.
But on the hour mark, it was level again thanks to Pélissié's strike.
Impossible to predict which way the game would go, each side had their moments. In fact, Toulon were defending superbly inside their own 22 for long spells, being pressed back as the hosts probed for a second try.
Toulon did have opportunities to retake the lead, but the pressure was getting to both sides as a place in the final four beckoned.
Machenaud missed another penalty with five to play, a big miss at a crucial time, but he didn't pass up the opportunity at another with two minutes remaining.
The French international scrum-half held his nerve from a penalty right in front of the posts to snatch the advantage back at a pivotal moment.
And despite a late push, Racing held on to defeat the reigning champions and seal their place in the final four.
Pens: Carter, Machenaud 3
Pens: Pélissié 3
Racing 92: 15 Brice Dulin, 14 Joe Rokocoko, 13 Johan Goosen, 12 Alexandre Dumoulin, 11 Juan Imhoff, 10 Dan Carter, 9 Maxime Machenaud, 8 Chris Masoe, 7 Bernard Le Roux, 6 Wenceslas Lauret, 5 Francois van der Merwe, 4 Luke Charteris, 3 Luc Ducalcon, 2 Dimitri Szarzewski, 1 Eddy Ben Arous
Replacements: 16 Camille Chat, 17 Khatchik Vartanov, 18 Martin Castrogiovanni, 19 Yannick Nyanga, 20 Manuel Carizza, 21 Mike Phillips, 22 Rémi Talès, 23 Marc Andreu
Toulon: 15 Delon Armitage, 14 Josua Tuisova, 13 Maxime Mermoz, 12 Ma'a Nonu, 11 James O’Connor, 10 Matt Giteau, 9 Jonathan Pélissié, 8 Duane Vermeulen, 7 Charles Ollivlon, 6 Juan Smith, 5 Romain Taofifenua, 4 Mamuka Gorgodze, 3 Manasa Paulo, 2 Guilhem Guirado, 1 Florian Fresia
Replacements: 16 Jean-Charles Orioli, 17 Xavier Chiocci, 18 Levan Chilachava, 19 Steffon Armitage, 20 Mathieu Bastareaud, 21 Tom Taylor, 22 Éric Escande, 23 Thibault Lassale
Referee: Wayne Barnes (England)
Assistant Referees: JP Doyle (England), Luke Pearce (England)
TMO: Graham Hughes (England)