Cardiff Blues 14-26 Saracens, Cardiff Arms Park
The win is Saracens' fourth win from as many games as they occupy the pole position in Pool 3 with Cardiff Blues at third place.
The Sarries got off to a fabulous start with Scotland international Sean Maitland crossing over in the ninth minute and Owen Farrell followed it with a conversion and a penalty goal to make it 0-10.
Cardiff Blues struck back with a well planned attack from scrum with centre Rey Lee-Lo going over the line that was improved by Gareth Anscombe to reduce the gap to three points.
Farrell kicked his second penalty goal to increase the visitors' lead to six points but it was the Welsh side that went into the break ahead following Dan Fish's try with Anscombe slotting the extras.
The England fly-half kicked his third three-pointer after the break to restore Sarries' lead but their momentum was jolted when Will Skelton was sin-binned in the 63rd minute but the Blues failed to make use of the opportunity and instead Jamie George crossed over in the 77th minute with Farrell kicking a conversion and a penalty goal on either side to complete a 14-26 win.
The Blues will take on Glasgow Warriors in the next round at Scotstoun Stadium while Saracens will lock horns with Lyon with both the games scheduled on 13th January.