Racing 92 booked a home Heineken Champions Cup quarter-final with a 46-33 bonus-point victory over the Scarlets in Paris.
A brace of tries from Simon Zebo plus a try apiece from Juan Imhoff, Henry Chavancy, Virimi Vakatawa and Teddy Iribaren was enough to overcome a resilient Scarlets side.
The Welsh region scored three tries of their own with Johnny McNicholl crossing twice and Steff Evans also touching down.
Racing grabbed the game's first try with a well-weighted kick through gathered by Chavancy who put another ball through for Imhoff to score.
But Scarlets enjoyed the majority of territory and possession in the first half with Dan Jones putting the Welsh region back into the lead with a penalty.
The visitors extended their lead with a well-worked try which resulted in Evans showing his pace to cross in the far left-hand corner after some neat handling by McNicholl and Jonathan Davies.
Racing hit back with Chavancy crossing as a result of a well-worked driving lineout from five metres out which came after Parkes was penalised for a high tackle.
The Parisians began to flex their muscles and Machenaud put them ahead for the first time in a tense encounter with a penalty from 30 metres out after a powerful scrum by the hosts.
But the visiting front-row gave Racing a taste of their own medicine shortly after with Samson Lee earning a penalty which allowed Jones to kick the west Walians into a 16-15 half-time lead.
The Scarlets scored first in the second half with Evans chipping over the top of the French side's defence allowing McNicholl to gather and score.
Racing regathered the kick off which out them on the front foot in the Scarlets 22. After a series of powerful carries they worked an overlap on the right-hand side with Zebo crossing at the corner.
Racing finally took the lead with Vakatawa hitting a strong line to brush Jones out of the way to score and secure his side's bonus-point try.
But the Scarlets kept coming back at last season's beaten finalists with Parkes charging forward into the Racing 22 to put his side on the attack before replacement prop Wyn Jones was held up over the try line.
Replacement scrum-half Iribaren put some breathing space between both sides when he darted over from short range after a powerful carry from Chavancy. And Zebo put the result beyond doubt when he gathered a pinpoint cross kick from Finn Russell to score.
The Scarlets finished the game in a positive fashion with McNicholl launching a scintillating counter attack from his own 22 with Josh Helps and Dan Davis helping to put their side on the attack. The ball was eventually recycled with Davies putting McNicholl over in the corner.