Saracens edged out Racing Metro 12-11 in dramatic circumstances at the Stade Olympique Yves-Du-Manoir to progress to the European Rugby Champions Cup semi-finals.
Marcelo Bosch won the game for a Sarries side now unbeaten in six outings, with what proved to be the final kick of the game.
Charlie Hodgson opened the scoring in Paris with a well-struck penalty, although the game almost swung the home side's way when they thought that they had successfully crossed over, only for referee Nigel Owens to rule it out.
Jim Hamilton was shown a yellow card with 27 minutes of the contest played for collapsing a maul close to his own try-line, and Racing's pressure finally told moments later as halfback Maxime Machenaud slipped past two defenders and crossed over for the only try of the afternoon.
There was to be no added extras, with Jonny Sexton clipping the post with his follow-up attempt, and when Hodgson split the sticks for a second time shortly before the interval, it meant that Sarries took a slender lead into the break.
A tense affair looked poised to continue into the second 40 minutes, but Alex Goode's successful kick opened up a four-point advantage for the Aviva Premiership side.
An important challenge from Bosch ensured that the visitors kept their lead intact, although Billy Vunipola gave away a penalty with 20 minutes left to play, allowing Machenaud to set up a thrilling finale to the last-eight clash.
Machenaud was at it again 10 minutes later to dramatically edge his side ahead late on, but there was more drama to come in the French capital as Bosch kicked over a penalty at the death to see Saracens progress.