A clinical Toulon gave their knock-out qualification chances a massive boost as they overcame London Irish 19-13 at Madejski Stadium on Sunday.
Such is the nature of this Pool of Death, this one went down to the wire and had Jonny Wilkinson held onto the ball over the whitewash early into the first-half, the French would probably have been 20 nil up minutes before the break.
But that spillage ultimately did not matter in the scheme of things as Wilkinson's 13 points from the tee, coupled by winger Rudi Wulf's try, meant that Irish were left with just a losing bonus-point ahead of next Saturday's reverse in Toulon.
Toulon captain and number eight Joe Van Niekerk was the outstanding player on the field and his arcing 50-metre break almost led to the opening try.
Van Niekerk split the Irish defence and then floated a pass over the top for Sackey but the move broke down when Joe El Abd spilled a simple pass.
He was not the last to do so from either side. Indeed, from the next handling error Toulon pounced to finally score the opening try they deserved.
Wilkinson seized possession from Seilala Mapasua's mistake and from there Toulon counter-attacked with precision.
The ball was moved wide for Van Niekerk, who linked first with Gabriele Lovobalavu and then Wulf, who streaked clear to touch down under the posts.
Lamb, who missed an early penalty shot at goal, then failed to find touch on successive occasions and Irish were almost punished again.
But Tagicakibau snatched a vital interception from Messina's inside pass to deny Toulon a try-scoring opportunity and instead transform it into one for the Exiles.
The Samoan powerhouse carried the ball up to halfway before slipping a delightful one-handed off-load to Chris Hala'ufia, who in turn fed Elvis Seveali'i.
Jonathan Joseph carried the attack down the right wing and then popped a pass off the ground for Delon Armitage, who kicked ahead and won the footrace to touch down.
Lamb's touchline conversion reduced Toulon's lead to 13-7 at the interval.
The visitors were unfortunate not to have been given a penalty try early in the second half when Sackey was taken out by Paul Hodgson as he chased down Lovobalavu's grubber kick.
The bounce of the ball defeated Hodgson and, with the ball crossing the line, all Sackey had to do was regather to score but he was brought down by the England scrum-half.
Referee Nigel Owens decided to play on and Irish did their best to cash in on their good fortune, with centres Mapusua and Seveali'i both forcing stiff defence from Wilkinson.
Steffon Armitage just failed to pick out Tagicakibau with a try begging and they had to settle eventually for another Lamb penalty.
Lamb missed the chance to draw Irish level but they stayed in the game after Toulon butchered a golden try-scoring opportunity.
Messina kicked ahead and regathered the ball on the Irish line. All he had to do was roll over to score but instead he threw a loose pass off the deck and Steffon Armitage cleaned up for Irish.
Reliable Wilkinson struck two more penalties to secure Toulon the victory but they could not kill off Irish.
Lovobalavu blocked Mapasua's clearance and fed replacement Laurent Magnaval but Wulf, under pressure from George Stowers, could not hold on and the ball went forward as he crossed the line.
Those wasted tries proved key - not to the result but for Irish, who snatched a losing bonus point with a late penalty from Dan Bowden.
For London Irish:
Try: D Armitage
Pen: Lamb, Bowden
Pen: Wilkinson 4
London Irish: 15 Delon Armitage, 14 Sailosi Tagicakibau, 13 Elvis Seveali'i, 12 Seilala Mapusua, 11 Jonathan Joseph, 10 Ryan Lamb, 9 Paul Hodgson, 8 Chris Hala'ufia, 7 Steffon Armitage, 6 Richard Thorpe, 5 Bob Casey, 4 Nick Kennedy, 3 Faan Rautenbach, 2 James Buckland, 1 Clarke Dermody.
Replacements: 16 Brian Blaney, 17 Alex Corbisiero, 18 Paulica Ion, 19 Kieran Roche, 20 George Stowers, 21 Topsy Ojo, 22. Dan Bowden, 23 Darren Allinson.
Toulon: 15 Benjamin Lapeyre, 14 Paul Sackey, 13 Geoffroy Messina, 12 Gabi Lovobalavu, 11 Rudi Wulf, 10 Jonny Wilkinson, 9 Pierre Mignoni, 8 Joe van Niekerk, 7 Joe El Abd, 6 Olivier Missoup, 5 Kris Chesney, 4 Dean Schofield, 3 Carl Hayman, 2 Sebastien Bruno, 1 Saimone Taumoepeau.
Replacements:16 Mickael Ivaldi, 17 Benjamin Basteres, 18 Mehdi Merabet, 19 Christian Loamanu, 20 Thomas Sourice, 21 Tom May, 22 Laurent Magnaval, 23 Jocelino Suta.
Referee: Nigel Owens