Paris - Holders Saracens kicked off their European Champions Cup campaign in style with eight tries in a 57-13 thrashing of Northampton on Sunday at Franklin's Gardens.
The two-time defending champions' display was reminiscent of the one that saw them thump Saints 55-24 at Twickenham on the opening day of the Premiership season.
A Liam Williams double helped Sarries storm into a 19-point lead early on, before former Northampton flanker Calum Clark sealed a bonus point before half-time.
Northampton were outscored eight tries to one as Saracens added four more in the second half.
Hooker Jamie George also outplayed opposite number Dylan Hartley in front of England coach Eddie Jones, as Saracens notched their biggest ever away win in Europe, which was Northampton's heaviest home defeat.
"It was definitely our best performance of the year and one of the real pleasing things was how long we sustained it for," Sarries director of rugby Mark McCall said.
"The group challenged themselves at half-time to maintain the intensity that was shown in the first half whether we had the ball or they had the ball."
Saracens go top of a perilous-looking Pool 2 ahead of Clermont, after the French side grabbed an impressive 26-21 victory at Ospreys.
Northampton next face a difficult trip to last year's losing finalists Clermont, where a defeat would leave their hopes already hanging by a thread.
"We came second best. The European champs proved why they are the champions," said Saints director of rugby Jim Mallinder.
"Sometimes you just don't see these things coming, like in the first game at Twickenham.
"Clearly they are the better team when they play us at this moment in time. We need to figure out why."
Fast hands across the back line opened up the home defence for the opening try, as an incisive pass from Owen Farrell was flicked on by American international Chris Wyles to send Williams over in the corner.
A driving maul from a five-metre line-out ended with centre Brad Barritt bundling over.
Northampton's first half went from bad to worse when British and Irish Lions winger George North was forced off with what looked to be a knee injury.
The visitors showed no mercy though, as Williams bagged his second try by bouncing off two tackles and touching down in the corner.
A big hit by Farrell on Ben Foden caused a scuffle that finally sparked the home crowd into life.
But the one-way traffic continued as Northampton lost David Ribbans to the sin bin and Clark touched down against his former club, with Farrell duly making it 29-6 at the break.
With the hosts still down to 14 at the start of the second period, Farrell's break created a simple try for Vincent Koch.
England prop Mako Vunipola powered through with 20 minutes left and Alex Lozowski ran clear to score under the posts.
Mikey Haywood finally gave the home fans something to cheer, but Northampton's misery was compounded as Ben Spencer scored an opportunistic eighth try.
Farrell kicked his seventh conversion to finish with 17 points.
Clermont grabbed their first away win of the season against Ospreys at the Liberty Stadium, after a rapid start that saw Alivereti Raka and Scott Spedding both score tries in the first 10 minutes.
Rhys Webb's try and Dan Evans' double set up a grandstand finale, but Spedding kicked a late long-range penalty as the French champions held on.
"We spent our time defending in the second half, but we were disciplined," said Clermont coach Franck Azema.
"It is good to have character, to snatch the victory in this way."
Earlier on Sunday, Toulon survived a Leigh Halfpenny-led fightback from Scarlets to edge to a 21-20 opening Pool 5 victory in southern France, and Castres battled to a 17-17 draw in Pool 4 with Munster.
European Champions Cup results:
Castres (FRA) 17 Munster (IRL) 17
Toulon (FRA) 21 Scarlets (WAL) 20
Ospreys (WAL) 21 Clermont (FRA) 26
Northampton (ENG) 13 Saracens (ENG) 57
Harlequins (ENG) 27 La Rochelle (FRA) 34
Leinster (IRL) 24 Montpellier (FRA) 17
Exeter (ENG) 24 Glasgow (SCO) 15
Racing 92 (FRA) 22 Leicester (ENG) 18
Bath (ENG) 23 Treviso (ITA) 0
Ulster (IRL) 19 Wasps (ENG) 9